GIFT  OF 
Professor  Charles  G.  Hyde 


1957 


^r<f* 


THE  UNITED  STATES  OFAMERICA 

PANAMA-PACIFIC  INTERNATIONAL  EXPOSITION 

SAN  FRANCISCO. M.CMJCV. 


GRAND  PRIZE  Certificate  and  GOLD  MEDAL 
awarded  W.  &  L.  E.  Gurley  for  Hydraulic 
Engineering  Instruments  at  the  Panama  -  Pacific 
International  Exposition,  San  Francisco,  1915. 


Manual 


Gurley  Hydraulic 
Engineering  Instruments 


First  Edition 

Price,  50  Cents 


W.  &  L.  E.  GURLEY,  Makers 

Established  1845 

TROY,  N.  Y.,  U.  S.  A. 

BRANCH  :  SEATTLE,  WASH. 


777 


/^  ^ 


COPYRIGHT,  1918 

BY 
W.  &  L.  E.  GURLEY 

TROY,  N.  Y.,  U.  S.  A. 


I  'BRAUY 


FOREWORD 


,£< 
The  importance  of  an    exact   knowledge    concerning   the 

surface  water  supply  of  the  country  has  been  recognized  for 
many  years.  The  immediate  necessity  for  stream  flow  data, 
to  be  used  by  those  interested  in  or  engaged  upon  problems  of 
hydraulic  engineering,  including  water  power,  domestic  water 
supply,  sewage  disposal,  inland  navigation,  irrigation,  swamp 
and  overflow  land  damage  and  flood  prevention,  has  created  a 
constantly  increasing  demand  for  accurate  stream  flow  measure- 
ments. 

The  relative  importance  of  the  different  uses  of  the  sur- 
face water  supply  of  the  country  varies,  not  only  in  different 
localities,  but  also  from  time  to  time  in  the  same  section  as  in- 
dustrial conditions  change.  These  uses  all  require  accurate 
quantitative  estimates  for  their  successful  application. 

Without  question  the  relation  of  stream  flow  records  to 
the  economic  development  of  the  country  is  one  of  continually 
increasing  interest.  The  desirability  of  investigating  its  water 
resources,  one  of  the  most  valuable  natural  assets  that  a  country 
possesses,  cannot  be  too  strongly  emphasized. 

Considering  these  facts  and  also  the  many  costly  exper- 
iences resulting  from  misinformation,  it  is  apparent  that 
all  data  must  be  collected  with  appropriate  equipment,  includ- 
ing properly  designed  and  well  constructed  instruments,  in 
order  to  be  accurate  and  dependable.  Inasmuch  as  it  is  usually 
impossible  to  predict  future  uses  of  stream  flow  data  at  the 
time  the  records  are  made, — in  many  cases  most  urgent  de- 
mands for  dependable  long  time  records  are  made  when  it  is 
impossible  to  produce  them, — all  stream  gaging  work  should 
progress  toward  the  collection  of  continuous  records  of  the 
highest  standard  of  accuracy.  The  energies  of  some  of  the 
foremost  engineers  of  the  world  have  been  given  to  this  work, 
and  as  a  result  both  methods  and  appliances  have  been  highly 
perfected. 

945358 


FOREWORD 

For  many  years  W.  &  L.  E.  Gurley  have  been  the  leaders 
in  the  manufacture  of  instruments  for  the  measurement  of 
water.  At  the  Panama-Pacific  International  Exposition  they 
were  given  the  highest  award  for  Hydraulic  Engineering 
Instruments. 

Every  part  of  these  instruments  is  constructed  from  care- 
fully selected  material,  and  is  accurately  made  and  finely 
finished  by  experienced  workmen  in  the  Gurley  Factory,  which 
has  been  producing  precision  instruments  and  equipment  for 
over  seventy  years.  They  consist  of  Engineering  and  Surveying 
Instruments,  such  as  Transits,  Levels,  Compasses,  Plane  Tables, 
Alidades,  Sketching  Cases,  Leveling  Rods  and  Stadia  Rods: 
and  Standard  Precision  Weights  and  Measures. 

The  methods  commonly  used  in  carrying  on  water 
measurements  are  described  in  standard  text  books,  to  which 
frequent  reference  has  been  made  in  preparing  this  Manual. 
We  are  indebted  to  prominent  hydraulic  engineers  for  sug- 
gestions and  photographs,  and  grateful  acknowledgment  is 
hereby  made  to  these  friends  for  their  co-operation,  as  well  as 
to  the  authors  quoted  in  this  book. 

W.  &  L.  E.  GURLEY 


CONTENTS 


PAGE 

FOREWORD 7_j 7 

PART  I. —  GURLEY  CURRENT  METERS — Their  Construction,  Care  and  Use  13 

INTRODUCTION    ^ ±* 13 

DESCRIPTION  OF  GURLEY  CURRENT  METER  AND  EQUIPMENT 14 

1. — The  Head 14 

2.— The  Tail  17 

3. — The  Hanger  and  Weights 17 

4. — The  Recording  or  Indicating  Device 18 

5. — The  Suspending  Device 19 

SELECTING  THE  PROPER  TYPE  OF  CURRENT  METER __  21 

ADVANTAGES  OF  GURLEY  CURRENT  METERS 1_  28 

COMPLETE  CURRENT  METER  FIELD  OUTFIT 29 

CARE  OF  THE  CURRENT  METER 30 

To  take  the  Meter  apart —  30 

To  change  Contact  Chambers 31 

Special  Instructions 31 

RATING  THE  CURRENT  METER 33 

TYPES  OF  CURRENT  METER  MEASUREMENTS  39 

Wading  Measurements 42 

Measurements  from  Cables 44 

Measurements  from  Bridges 47 

USE  OF  THE  CURRENT  METER 48 

Soundings    48 

Velocity   Observations    49 

Recording  the  Data 52 

Low  Water  Measurements 57 

Measurements  under  Ice  59 

Measurements  in  Artificial  Channels 62 

ACCURACY  AND  RELIABILITY  OF  THE  CURRENT  METER 62 

SELECTION  AND  LOCATION  OF  GAGING  STATIONS 63 

Reconnoissance    63 

Observers 70 

Establishment  of  .  Stations 70 

GAGES    71 

Non-Recording  Gages 72 

Gurley  Hook  Gage 73 

Recording  Water  Stage  Registers 75 

BENCH  MARKS   75 

PART  II. —  GURLEY  AUTOMATIC  WATER  STAGE  REGISTERS  —  Their  Con- 
struction, Installation  and  Operation 77 

INTRODUCTION    77 

CONDITIONS     REQUIRING    THE    USE    OF   AUTOMATIC    WATER    STAGE 

REGISTERS 77 

1. — Where  water  is  valuable  and  exceptionally  accurate  records 

are  necessary. 78 

2. — Where  artificial  or  natural  stream  conditions  cause  endless 

changes  in  stage  in  24  hours. 78 

3. — Where  records  are  desired  on  a  flood-water  stream  which 

is  dry  most  of  the  year. 78 


CONTENTS 

PAGE 

4. — Where  complete  records  are  desired  on   a   stream  which 

flows  continuously  but  is  subject  to  endless  floods. 79 

5. — Where  it   is  necessary   to   determine   the   maximum   gage 

height  or  the  maximum  daily  mean  gage  height. 79 

6. — Where  it  is  necessary  to    determine    the    minimum    gage 

height  or  the  minimum  daily  mean  gage  height. 80 

7. — Where  small  streams  of  sudden  fluctuation  are  measured 

by  weirs  for  adjudication  of  water  by  the  courts. 80 

8. — Where  available  gage  readers  do  not  have  sufficient  intelli- 
gence to  read  a  gage,  or  cannot  be  trusted. 80 

9. — Where  the  station  is  situated  at  an  isolated  point  and  a 

gage  reader  is  not  available. 81 

ESSENTIAL  FEATURES  OF  AUTOMATIC  WATER  STAGE  REGISTERS 81 

The  Float   82 

The  Transfer  Mechanism 84 

The  Record  Sheets 84 

The  Clock   85 

The  Cover  85 

TYPES  OF  GURLEY  AUTOMATIC  WATER  STAGE  REGISTERS 85 

Gurley  Printing  Water  Stage  Register 86 

Advantages    86 

Construction    90 

Installation  and   Operation 96 

Gurley  Graphic  Water  Stage  Register  — 10  foot  Range 101 

Advantages    101 

Construction    ' 104 

Installation  and  Operation   107 

Gurley  Graphic  Water  Stage  Register  —  1  foot  Range 110 

Advantages    112 

Construction    112 

Installation  and  Operation 113 

INSTALLATION  AND  SHELTER  OF  WATER  STAGE  REGISTERS 118 

CARE  AND  COMPUTATION  OF  RECORDS  122 

OTHER    APPLICATIONS    OF    GURLEY    CURRENT    METERS    AND    WATER 

STAGE  REGISTERS  128 

Measurement  of   Sewage   129 

Soundings  and  Tide  Gages 131 

Navigation  Canals 133 

Hydraulic  Power  Stations 133 

Flumes   133 

Weirs    133 

SUGGESTIONS    FOR    THE    SELECTION   .OF    AUTOMATIC    WATER    STAGE 

REGISTERS    136 

Printing   Register   137 

Graphic  Registers 137 

INDEX    141 

PRICE  LIST  _  _  IN  COVER  POCKET 


ILLUSTRATIONS 


PAGE 

GRAND  PRIZE  CERTIFICATE  AND  Goib  MEDAL FRONTISPIECE 

FIG.  1. —  Gurley  Current  Meter  and  Attachments 15 

2. —  Reel  for  use  with  Current  Meter 20 

3. —  No.  616  Acoustic  Current  Meter 21 

4. —  NO.  618  Electric  Current  Meter 22 

5. —  No.  617  Electric  Current  Meter 23 

6.— No.  621  Electric  Current  Meter 23 

7. —  No.  623  Electric  Current  Meter,  suspended  by  cable 24 

8. —  No.  623  Electric  Current  Meter,  suspended  by  wading  rod 24 

9. —  Nos.  617,  621  or  624  Current  Meter,  attached  to  wading  rod 

by  double  end  hanger. 25 

lO.—  No.  600  Electric  Current  Meter 26 

11, —  NO.  609  Electric  Register 26 

12. —  Special   Fibre   Carrying   Case   27 

13. —  Testing  Meter   Circuit   32 

14.— Testing  Meter  Circuit   32 

15. —  Testing  Meter  Circuit   32 

16. —  Current  Meter  Rating  Station  at  U.  S.  Bureau  of  Standards  33 

17. —  Current  Meter  Rating  Station    of    Canadian    Interior    Dept.  34 

18. —  Boat  equipped  for  Current  Meter  Measurements 39 

19. —  Catamaran  equipped  for  Current  Meter  Measurements 39 

20. —  Natural  Control  of  a   Stream   41 

21. —  Artificial  Control  of  a  Stream 41 

22. —  Wading  Measurement 43 

23. —  Typical  Gaging  Station  for  Wading  Measurement 43 

24. —  Current  Meter  Gaging  Station  44 

25. —  Typical  Current  Meter  Gaging  Station  with  Automatic  Water 

Stage  Register  45 

26. —  Current  Meter  Observers  in  Cable  Car 45 

27. —  Russian  Government  Engineers  using  Gurley  Current  Meters 

in  Turkestan 46 

28. —  Typical  Gaging  Station  for  Bridge  Measurement 47 

28a. —  Form  No.  H-325,  Discharge  Measurement,  General  Data 54 

28b. —  Form  No.  H-326,  Current  Meter  Notes 55 

29. —  Cross-section  of  Stream,  to  illustrate  Discharge  Measurement 

Computation    56 

30. —  Winter   Measurement   57 

31. —  Current  Meter  Measurements  in  Winter 58 

32. —  Current  Meter  Measurements  in  Winter 58 

33. —  Current  Meter  Measurements  in  Winter 58 

34. —  Diagram    indicating    Notation    used    in    making    Discharge 

Measurements  under  Ice,  with  Form  for  Notes 60 

35. —  Ice  Chisel,  Ice  Measuring  Stick,  and  Bag 61 

36. —  Winter   Measurement    61 

37. —  Showing  improper  location  of  Gaging  Stations 66 

38. — 'Showing  improper  location  of  Gaging  Stations 68 

39. —  Showing  improper  location  of  Gaging  Stations 69 

40. —  Vertical  and  Inclined  Staff  Gages 72 


ILLUSTRATIONS 


PAGE 

FiG.41. —  No.  628  Hook  Gage 73 

42. —  U.  S.  Geological  Survey  Bench  Mark 76 

43. —  Section  of  Paper  Tape  used  on  Printing  Register 86 

44.— No.  630  Printing  Water  Stage  Register 87 

45. —  No.  630  Printing  Water  Stage  Register 89 

46. —  No.  632  Tape  Reel  90 

47. —  No.  630  Printing  Water  Stage  Register 91 

48. —  No.  630  Printing  Water  Stage  Register 93 

49. —  Details  of  Installation  of  Printing  Register 95 

50. —  No.  633  Graphic  Water  Stage  Register 103 

51. —  No.  633  Graphic  Water  Stage  Register 105 

52. —  No.  636  Graphic  Water  Stage  Register 106 

53. —  Showing  method  of  inserting  ends  of  the  Record  Sheet 108 

54. —  No.  634  Graphic  Water  Stage  Register 111 

55.— No.  634  Graphic  Water  Stage  Register 113 

56. —  Record  Sheet  for  No.  633  or  No.  636  Graphic  Register 116 

57. —  Record  Sheet  for  No.  634  Graphic  Register 117 

58. —  Portable  Shelter  for  Water  Stage  Register 118 

59. —  Device  for  reducing  quantity  of  oil  used  as  a  cover  in  wells  121 

60. —  Reinforced  Concrete  Well  and  Shelter 123 

61. —  Concrete  Shelter  123 

62.— Metal  Shelter  and  Well 124 

63. —  Metal  Shelter  with  door  open 124 

64.— Wooden  Well  and  Shelter  125 

65. —  Water  Stage  Register  installation  in  California 125 

66. —  Wooden  Well  and  Shelter  installed  at  a  Bridge  Abutment  ___  126 

67. —  Wooden  Well  and  Shelter  installed  against  a  Bridge  Pier  __ _  126 

68. —  Form  for  Inspection  of  Recording  Register  Stations 127 

69. —  Installation  of  a  Graphic  Register  in  manhole  of  a  Sewer 129 

70. —  Installation  of  a  Graphic  Register  on  New  York  State  Barge 

Canal  132 

71. —  Installation  of  a  Graphic  Register  on  New  York  State  Barge 

Canal  132 

72. —  Installation  of  a  Graphic  Register  on  New  York  State  Barge 

Canal  132 

73. —  Installations  of  Printing  and  Graphic  Registers  in  connection 

with  the  Keokuk  Dam 134 

74. —  Installation  of  a  Register  at  a  Weir 135 


Manual 

of 

Gurley  Hydraulic  Engineering  Instruments 


PART  I.  . 

GURLEY  CURRENT  METERS  V  A; 

(PRICE  PATENTS) 
THEIR  CONSTRUCTION,  CARE  AND  USE* 

INTRODUCTION 

For  more  than  thirty  years  W.  &  L.  E.  Gurley  have  made 
Current  Meters  under  the  patents  of  W.  G.  Price,  the  Assistant 
Engineer  of  the  Corps  of  Engineers,  United  States  Army,  who 
in  1885  devised  the  initial  pattern.  The  general  features  are 
retained  in  the  latest  models,  although  somewhat  modified  as 
the  result  of  suggestions  from  many  hydraulic  engineers  who 
have  had  large  experience  in  current  meter  observation  under 
all  conditions  of  service. 

The  many  hundreds  of  Gurley  Current  Meters  in  use  in 
all  parts  of  the  world,  their  constantly  increasing  sale  and  their 
accuracy  and  reliability  under  all  conditions,  show  that  they 
are  the  standard  instruments  for  the  accurate  measurement  of 
the  velocity  of  water  in  streams  and  open  conduits. 

A  current  meter  for  measuring  the  velocity  of  flowing 
water  comprises  two  essential  parts:  (a)  a  wheel  arranged 
so  that  when  suspended  in  flowing  water  the  pressure  of  the 
water  against  it  causes  it  to  revolve;  (b)  a  device  for  recording 
or  indicating  the  number  of  revolutions  of  this  wheel.  The 
relation  between  the  velocity  of  the  moving  water  and  the  revo- 
lutions of  the  wheel  is  determined  by  rating  each  meter. 

*  Largely  quoted  from  "  The  use  and  care  of  the  current  meter,  as 
practised  by  the  U.  S.  Geological  Survey,"  by  John  C.  Hoyt,  Trans.  Am. 
Soc.  C.  E.,  volume  66,  page  70,  1910. 

"  River  Discharge,"  by  Hoyt  &  Grover,  for  sale  by  W.  &  L.  E.  Gurley, 
price  $2.00  postpaid,  gives  a  complete  treatise  of  the  methods  of  collecting 
and  analyzing  stream-flow  data.  In  the  preparation  of  this  Manual  this 
book  has  been  largely  used  and  many  direct  quotations  are  made  from  it. 


ILLUSTRATIONS 


PAGE 

Fio.41. —  No.  628  Hook  Gage 73 

42. —  U.  S.  Geological  Survey  Bench  Mark 76 

43. —  Section  of  Paper  Tape  used  on  Printing  Register 86 

44.— No.  630  Printing  Water  Stage  Register 87 

45. —  No.  630  Printing  Water  Stage  Register 89 

46. —  No.  632  Tape  Reel  90 

47. —  No.  630  Printing  Water  Stage  Register 91 

48. —  No.  630  Printing  Water  Stage  Register 93 

49. —  Details  of  Installation  of  Printing  Register 95 

50. —  No.  633  Graphic  Water  Stage  Register 103 

51. —  No.  633  Graphic  Water  Stage  Register 105 

52. —  No.  636  Graphic  Water  Stage  Register 106 

53. —  Showing  method  of  inserting  ends  of  the  Record  Sheet 108 

54. —  No.  634  Graphic  Water  Stage  Register 111 

55.— No.  634  Graphic  Water  Stage  Register 113 

56. —  Record  Sheet  for  No.  633  or  No.  636  Graphic  Register 116 

57. —  Record  Sheet  for  No.  634  Graphic  Register 117 

58. —  Portable  Shelter  for  Water  Stage  Register 118 

59. —  Device  for  reducing  quantity  of  oil  used  as  a  cover  in  wells  121 

60. —  Reinforced  Concrete  Well  and  Shelter 123 

61.— Concrete  Shelter  125 

62.— Metal  Shelter  and  Well 124 

63. —  Metal  Shelter  with  door  open 124 

64. —  Wooden  Well  and  Shelter  125 

65. —  Water  Stage  Register  installation  in  California 125 

66. —  Wooden  Well  and  Shelter  installed  at  a  Bridge  Abutment  ___  126 

67. —  Wooden  Well  and  Shelter  installed  against  a  Bridge  Pier  ___  126 

68. —  Form  for  Inspection  of  Recording  Register  Stations 127 

69. —  Installation  of  a  Graphic  Register  in  manhole  of  a  Sewer 129 

70. —  Installation  of  a  Graphic  Register  on  New  York  State  Barge 

Canal  132 

71. —  Installation  of  a  Graphic  Register  on  New  York  State  Barge 

Canal  132 

72. —  Installation  of  a  Graphic  Register  on  New  York  State  Barge 

Canal  132 

73. —  Installations  of  Printing  and  Graphic  Registers  in  connection 

with  the  Keokuk  Dam 134 

74. —  Installation  of  a  Register  at  a  Weir 135 


Manual 

of 

Gurley  Hydraulic  Engineering  Instruments 


PART  I.  . 

GURLEY  CURRENT  METERS v A- 

(PRICE  PATENTS) 
THEIR  CONSTRUCTION,  CARE  AND  USE* 

INTRODUCTION 

For  more  than  thirty  years  W.  &  L.  E.  Gurley  have  made 
Current  Meters  under  the  patents  of  W.  G.  Price,  the  Assistant 
Engineer  of  the  Corps  of  Engineers,  United  States  Army,  who 
in  1885  devised  the  initial  pattern.  The  general  features  are 
retained  in  the  latest  models,  although  somewhat  modified  as 
the  result  of  suggestions  from  many  hydraulic  engineers  who 
have  had  large  experience  in  current  meter  observation  under 
all  conditions  of  service. 

The  many  hundreds  of  Gurley  Current  Meters  in  use  in 
all  parts  of  the  world,  their  constantly  increasing  sale  and  their 
accuracy  and  reliability  under  all  conditions,  show  that  they 
are  the  standard  instruments  for  the  accurate  measurement  of 
the  velocity  of  water  in  streams  and  open  conduits. 

A  current  meter  for  measuring  the  velocity  of  flowing 
water  comprises  two  essential  parts:  (a)  a  wheel  arranged 
so  that  when  suspended  in  flowing  water  the  pressure  of  the 
water  against  it  causes  it  to  revolve;  (b)  a  device  for  recording 
or  indicating  the  number  of  revolutions  of  this  wheel.  The 
relation  between  the  velocity  of  the  moving  water  and  the  revo- 
lutions of  the  wheel  is  determined  by  rating  each  meter. 

*  Largely  quoted  from  "  The  use  and  care  of  the  current  meter,  as 
practised  by  the  U.  S.  Geological  Survey,"  by  John  C.  Hoyt,  Trans.  Am. 
Soc.  C.  E.,  volume  66,  page  70,  1910. 

"  River  Discharge,"  by  Hoyt  &  Grover,  for  sale  by  W.  &  L.  E.  Gurley, 
price  $2.00  postpaid,  gives  a  complete  treatise  of  the  methods  of  collecting 
and  analyzing  stream-flow  data.  In  the  preparation  of  this  Manual  this 
book  has  been  largely  used  and  many  direct  quotations  are  made  from  it. 


14          W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

The  essentials  of  a  good  current  meter  are  (a)  simplicity 
in  construction,  with  no  delicate  parts  which  easily  get  out  of 
order;  (b)  a  small  area  of  resistance  to  the  velocity  of  the 
water;  (c)  a  simple  and  effective  device  for  indicating  the 
number  of  revolutions  of  the  wheel;  and  (d)  easy  adaptability 
to  use  under  all  conditions. 


DESCRIPTION  OF  THE  GURLEY  CURRENT 
METER  AND  EQUIPMENT 

The  small  Gurley  Current  Meter  and  equipment  consists 
of  five  pincipal  parts:  (1)  the  head;  (2)  the  tail;  (3)  the 
hanger  and  weights;  (4)  the  recording  or  indicating  device; 
and  (5)  the  suspending  device.  In  the  following  descriptions 
the  numbers  in  parentheses  refer  to  Fig.  1. 

1.  THE  HEAD.  The  head  consists  of  a  ID -shaped  yoke  (1) 
carrying  a  wheel  made  of  six  conical  cups  (2),  attached  to  a 
horizontal  frame  (3).  This  wheel,  referred  to  as  the  cups, 
turns  in  a  counter  clockwise  direction  on  a  vertical  axis  known 
as  the  cup  shaft,  which  rests  and  revolves  on  a  pivot  point  bear- 
ing at  the  lower  end  and  engages  the  recording  mechanism  at 
the  upper  end. 

The  Cup  Shaft  consists  of  two  parts  (4,  5)  clamping  the 
cup  frame.  They  are  screwed  together  from  either  side  of  the 
frame,  thus  fastening  the  cups  rigidly  and  at  right  angles  to  the 
cup  shaft.  At  the  lower  part  of  the  cup  shaft  there  is  a  bucket 
nut  having  a  pivot  bearing  which  receives  the  pivot  point  (6) 
on  which  the  cups  revolve. 

The  Pivot  Point  is  screwed  through  a  metal  bushing  (7) 
known  as  the  frame  nut,  and  is  firmly  held  by  a  lock-nut  (8). 
The  frame  nut  slides  into  the  lower  arm  of  the  yoke,  and  is 
clamped  in  position  by  a  set-screw.  By  means  of  a  raising  nut 
(9)  on  the  lower  part  of  the  shaft,  the  cups  should  always  be 
lifted  from  the  pivot  point  when  the  meter  is  not  in  use.  '  This 
raising  nut  has  a  left-hand  thread,  so  that  it  will  not  tighten 
when  the  cups  revolve  when  in  use. 

The  upper  part  of  the  cup  shaft  is  fitted  with  either  a 
worm  gear  or  an  eccentric  that  passes  into  a  cylindrical  chain- 


CURRENT    METERS 


15 


Scale,  in  inches 
0        1        ?.?*.?« 


FIG.  1. —  Gurley  Current  Meter  and  Attachments. 


16  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

her  (10),  known  as  the  contact  chamber.  This  chamber  con- 
tains the  mechanism  for  making  the  contact  which  indicates 
the  revolutions  of  the  cups.  The  construction  and  arrangement 
of  both  the  contact  chamber  and  the  mechanism  contained  in 
it  depend  on  whether  the  indicating  device  is  penta-count  elec- 
tric, single-count  electric,  or  acoustic. 

When  the  penta-count  electric  indicating  device  is  used, 
the  contact  chamber  (10)  which  is  closed  by  a  screw  cap  (11), 
provided  with  a  leather  gasket  for  keeping  out  the  water,  is 
held  by  a  sliding  fit  in  the  upper  end  of  the  yoke,  and  is 
clamped  in  position  by  a  set-screw.  In  the  contact  chamber 
there  is  fitted  a  cylindrical  plug  (12)  which  is  held  in  position 
by  a  screw  and  carries  a  gear-wheel  (13).  This  engages  the 
worm  gear  on  the  upper  end  of  the  cup  shaft,  the  gearing  being 
so  arranged  that  the  wheel  makes  one  revolution  for  every 
twenty  revolutions  of  the  cups.  On  the  side  of  the  wheel  are 
four  pins,  equally  spaced  and  set  so  that  they  will  strike  the 
contact  spring  (14)  at  each  fifth  revolution  of  the  cups,  thus 
closing  the  electric  circuit  to  the  indicating  device,  explained 
later.  These  contact  parts  are  known  as  the  contact  wheel,  the 
contact  pins,  and  the  contact  spring.  The  contact  spring  is 
carried  by  the  contact  plug  (15)  which  is  screwed  into  the 
contact  chamber  through  a  hard-rubber  bushing  (16)  that  in- 
sulates the  contact  spring  from  all  other  parts  of  the  meter 
when  it  is  not  touching  one  of  the  pins  on  the  contact  wheel. 
In  the  outer  end  of  the  contact  plug  there  is  a  hole  and  a  set- 
screw  for  connecting  one  wire  from  the  indicating  device. 

When  the  single-count  electric  indicating  device  is  used, 
the  contact  chamber  (lOa)  and  appurtenances  are  the  same  as 
described  for  the  penta-count  contact  chamber,  with  the  ex- 
ception that  the  gear  wheel  (13)  is  omitted  and  the  worm  gear 
on  the  upper  part  of  the  shaft  (4)  is  replaced  by  the  eccentric 
(4a)  that  strikes  the  contact  spring  (14a)  at  each  revolution, 
thus  closing  the  electric  circuit  to  the  indicating  device.  The 
penta-  and  single-count  contact  chambers  are  interchangeable. 

The  electric  indicating  device  is  used  when  the  meter  is 
suspended  from  a  meter  cord  attached  to  the  stem  (23),  or  is 
held  by  a  rod  either  screwed  into  the  coupling  (57),  or  sliding 
through  the  connection  (54). 


CURRENT    METERS 17 

When  the  acoustic  indicating  device  is  used,  the  contact 
chamber  (lOb)  is  closed  with  a  cap  (lib)  fitted  with  a  metal 
drum  (49),  and,  in  place  of  the  contact  spring  (14)  and  plug 
(16),  there  is  a  small  harnmer  (50)  which  is  caused  by  the 
pins  on  the  side  of  the  gear-wheel  (13a)  to  strike  the  drum 
at  each  tenth  revolution  of  the  cups.  In  order  to  keep  the 
water  from  deadening  the  sound  by  rising  into  the  contact 
chamber  (lOb),  it  is  raised  about  four  inches  above  the  yoke 
(la)  by  inserting  the  tube  (59)  and  lengthening  the  upper 
part  of  the  shaft  (4a).  The  acoustic  meter  is  always  sup- 
ported on  a  rod  (51)  attached  to  the  contact  chamber. 

2.  THE  TAIL.  The  tail  is  used  when  the  meter  is  suspended 
by  a  cable,  or  on  a  sliding  hanger  rod.     It  balances  the  head? 
and  also  keeps  the  axis  of  the  meter  parallel  to  the  direction 
of  the  current.     It  consists  of  a  stem  (17)  which  is  held  by  a 
sliding  fit  into  a  socket  in  the  stem  of  the  yoke,  in  which  it  is 
clamped  by  a  set-screw.     On  this  stem  there  are  two  vanes  (18 
and  19)  set  at  right  angles.     One  of  the  vanes  is  rigidly  at- 
tached to  the  stem;  the  other  fits  into  grooves  on  the  first  and 
may  be  pulled  out  readily  when  the  key  (20)  that  holds  it  in 
place  is  turned.     On  one  of  the  vanes  there  is  a  slot  carrying 
a  weight  (21)  that  can  be  adjusted  to  balance  the  meter. 

3.  THE  HANGER  AND  WEIGHTS.  When    suspended   by    a 
cable,  the  meter  is  hung  by  a  screw-bolt  (22)  on  a  steel  stem 
(23)  that  passes  through  a  slot  in  the  stem  of  the  yoke.    The  slot 
in  the  stem  of  the  yoke  is  wide  enough  to  allow  the  meter  to 
swing  freely  in  a  vertical  plane,  and  the  bolt  passes  through 
the  frame  a  little  above  the  center  of  gravity  of  the  meter,  so 
that  the  latter  will  readily  adjust  itself  to  a  horizontal  position. 
In  the  upper  end  of  the  hanger  there  is  a  hole  for  attaching 
the  suspended  cable,  and  at  intervals  along  the  stem  there  are 
other  holes  by  which  the  meter  and  lead  weights  may  be  hung. 
The  weights  (24)  are  of  torpedo  shape, — a  design  which  offers 
the  least  resistance  to  the  current, — and    are    made    in    three 
sizes  weighing,  respectively,  6%,  10  and  15  pounds.     They 
are  attached  to  the  stem  by  a  screw  bolt.     The  order  in  which 
the  weights  and  meter  are  placed  on  the  stem,  depends  on  the 
conditions  under  which  the  measurements  are  to  be  made. 


18  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

When  the  meter  is  used  on  a  rod,  the  hanger,  the  weights, 
and  sometimes  the  tail  are  dispensed  with. 

The  set-screws  for  clamping  the  various  sliding  fits  are 
all  of  the  same  size  and  are  of  standard  make.  Beveled  grooves 
are  provided  in  each  of  these  connections,  so  that  when  the 
set-screws  engage  them  the  parts  are  drawn  into  place. 

All  parts  of  the  meter  are  standard,  and  can  readily  be 
replaced  in  the  field.  Parts  should  always  be  ordered  by  Shop 
Number  from  the  illustrations  in  the  Price  List. 

4.  THE  RECORDING  OR  INDICATING  DEVICE.  A  recording 
or  indicating  device  is  necessary  for  determining  the  number  of 
revolutions  of  the  meter  wheel,  and  the  successful  use  of  the 
meter  depends  largely  on  this  part  of  the  apparatus.  Various 
devices,  operated  either  on  the  mechanical,  electric,  or  acoustic 
principle,  have  been  used  for  this  purpose.  These  include  the 
telegraph  ticker,  automatic  recorder,  electric  buzzer,  telephone 
receiver,  drums,  etc.  Of  these,  however,  the  telephone  receiver 
and  the  acoustic  indicator  have  been  found  to  be  most  satisfac- 
tory in  general  practice. 

The  telephone  attachment  consists  of  a  telephone  receiver 
(25)  and  small  battery  (26)  placed  in  a  partial  circuit  which 
terminates  in  a  connecting  plug  (27)  by  means  of  which  the 
apparatus  can  be  readily  connected  in  circuit  with  the  meter. 
The  magnets  of  the  telephone  receiver  are  wound  so  as  to  se- 
cure a  loud  click. 

The  dry  battery  (26)  is  compact  and  can  be  renewed 
readily.  It  is  enclosed  in  a  nickel-plated  case  similar  in  shape 
to  that  of  a  fountain  pen.  This  case  is  equipped  with  a  con- 
necting plug  to  receive  the  two  wires. 

In  use,  the  telephone  receiver  is  fastened  on  the  shoulder 
by  a  large  safety  pin,  or  is  held  at  the  ear  by  an  operator's 
head  band,  which  is  worn  under  the  cap,  if  preferred.  The 
battery  cell  is  placed  in  the  coat  or  trousers  pocket.  The  con- 
necting plug  (27)  should  hang  below  the  shoulders  and  be 
easily  accessible  for  attaching  and  detaching  the  meter  circuit. 

In  the  acoustic  indicator,  the  striking  of  the  hammer  (50) 
on  the  drum  (49)  in  the  contact  chamber  (lOb)  indicates 
each  tenth  revolution  of  the  meter,  as  already  explained.  The 
sound  is  transmitted  through  the  rods  (51)  and  a  rubber  tube 


CURRENT    METERS 19 

to  the  ear  of  the  operator.    The  rubber  end  and  ear-piece  are 
not  necessary  unless  there  is  considerable  noise. 

Audible  indicators,  such  as  the  telephone  and  the  acoustic 
signalling  device,  have  the  advantage  of  enabling  the  operator 
to  detect  any  irregularities  caused  by  trouble  with  the  meter, 
battery,  electric  circuit,  or  any  part  of  the  equipment.  A  stop- 
watch is  necessary  for  the  proper  observation  of  time. 

Electric  recording  devices  are  sometimes  used,  particu- 
larly when  measuring  the  discharge  of  large  navigable  streams. 
For  this  purpose  specially  designed  boats  manned  by  several 
assistants  are  used. 

5.  THE  SUSPENDING  DEVICE.  The  suspending  device,  which 
consists  of  a  rod  or  of  some  form  of  cable,  must  provide  for 
lowering  the  meter  and  weight  into  the  water  and  also  for  com- 
pleting an  electric  circuit  which  includes  the  contact  chamber, 
the  meter,  and  the  recording  device. 

The  rod  in  common  use  in  connection  with  the  electric 
recorder  consists  of  a  %  inch  tube  (55)  graduated  to  feet  and 
tenths.  For  convenience  in  carrying,  it  is  made  in  1.0,  1.5  or 
2  foot  sections  fitted  with  screw  threads,  the  2  foot  section  be- 
ing standard.  The  sections  of  the  rod  are  connected  by  flush 
joints  which  offer  no  obstruction  to  the  movement  of  the  sliding 
hanger. 

Two  methods  of  hanging  the  meter  on  the  rod  are  in  use. 
By  the  first  the  head  and  tail  of  the  meter  are  attached  to  a 
sliding  hanger  (54),  which  can  be  moved  up  and  down  the 
rod  or  clamped  in  any  position.  On  the  bottom  of  the  rod 
there  is  a  flat  base  (53)  which  keeps  it  from  sinking  into  the 
bed  of  the  stream,  and  at  the  top  there  is  a  plug  (56)  for  con- 
necting one  of  the  wires  from  the  recording  device.  The  cir- 
cuit between  the  meter  cups  and  the  recording  device  is  made 
by  attaching  one  of  the  wires  from  the  recording  device  to  the 
plug  in  the  top  of  the  rod.  The  other  wire  follows  down  the" 
rod  and  is  attached  to  the  contact  plug  of  the  meter.  In  the 
second  method  the  rod  (58)  is  connected  by  the  screw  socket 
(57)  in  the  yoke. 

The  rods  (51)  for  use  with  either  type  of  meter  are  of  % 
inch  tubing  graduated  to  feet  and  tenths  and,  for  convenience 
in  carrying,  are  made  in  1.0,  1.5,  or  2  foot  sections  which  screw 


20 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


together.  The  bottom  rod  connects  with  the  contact  chamber 
(49)  by  a  screw,  and  is  cut  so  that  the  zero  reading  is  the  plane 
of  the  center  of  the  cups.  On  the  upper  end  of  the  top  rod 
there  is  a  flat  plate  (52)  in  the  center  of  which  there  is  a  hole 
through  which  the  sound  from  the  drum  can  be  heard.  The 
soundings  are  made  with  this  end  of  the  rod,  and  the  plate 
keeps  the  end  from  sinking  into  the  bed  of  the  stream. 

The  meter  cables  must  be  strong  enough  to  support  the 
weight  required  to  hold  the  meter  in  place  while  making  obser- 
vations, must  be  water-proof  to  avoid  short  circuits  and  must 
be  tough  and  flexible  to  withstand  hard  usage.  They  should 
be  as  small  in  diameter,  consistent  with  strength,  as  is  possible, 
in  order  to  offer  small  resistance  to  the  water.  They  may  be 
graduated  in  feet  by  means  of  markers,  for  convenience  in 
measuring  depths.  Greater  precision  in  such  measurements 
is  obtained  by  using  a  single  index  point  and  applying  it  to  a 
fixed  scale.  This  method  eliminates  the  effect  of  any  possible 
stretch  in  the  cable.  When  used  on  a  cable  reel,  (See  Fig.  2) 
the  scale  and  index  are  part  of  the  reel. 

Reels  should  be  used  at  any  place  where  a  considerable 
number  of  measurements  are  to  be  made,  both  as  a  matter  of 
convenience  in  handling  the  equipment  and  to  protect  the  elec- 


FIG.  2. —  Reel  for  use  with  Gurley  Current  Meter.     Designed  for  use  on  a 

railroad  bridge  having  a  narrow  foot  walk.  The  reel  is  fastened  on  the 

side  opposite  the  meter,  so  as  to  prevent  it  from  tipping. 


CURRENT    METERS 


21 


trie  circuits  in  the  meter  cable  from  the  effects  of  twisting  and 
abrasion. 

SELECTING  THE  PROPER  TYPE  OF  CURRENT  METER 

Gurley  meters  are  made  in  several  different  patterns,  thus 
allowing  a  wide  range  for  selection. 

The  selection  should  be  made  after  consideration  has  been 
given  to  the  following  factors: 

( 1 )  The  purpose  for  which  the  instrument  is  to  be  used. 

(2)  The  manner  in  which  it  is  supported. 

(3)  The  amount  of  weight  to  be  used. 

(4)  The  frequency  of  the  revolutions  to  be  indicated. 
When  it  is  possible  for  the  observer  to  approach  the  stream 

closely,  and  to  hold  the  meter  in  position  by  means  of  its  sus- 
pension rod,  especially  in  channels  of  small  depth,  the  Accous- 
tic  Current  Meter  No.  616  is  very  useful.  This  meter  indicates 
every  tenth  revolution. 

No.  616,  the  Acoustic  Current  Meter,  is  so  called  because 
the  revolutions  of  the  bucket  wheel  are  indicated  by  the  sound 


FIG.  3. —  No.  616  Acoustic  Current  Meter,  with  jointed  wading  rod, 

rubber  tube  and  ear  piece. 
Indicating  every  tenth  revolution. 


22  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

of  a  hammer  striking  against  a  diaphragm,  one  blow  for  every 
10  revolutions.  The  indicating  mechanism  is  completely  en- 
closed and  thoroughly  protected  from  injury.  When  in  use  the 
meter  is  held  by  a  jointed  hollow  rod,  which  screws  into  the 
frame  and  in  connection  with  a  rubber  tube  and  ear  piece 
attached  to  it,  forms  a  passage  through  which  the  sound  of  the 
hammer  stroke  is  transmitted  to  the  ear  of  the  observer.  This 
enables  him  to  count  the  number  of  revolutions  of  the  wheel  in 
any  given  space  of  time,  and  then  by  means  of  the  reduction 
table  to  ascertain  the  velocity  of  flow. 

Many  observers  prefer  an  electric  type  of  revolution  indi- 
cator. In  some  cases  it  is  desirable  to  have  more  than  one 
person  hear  and  bear  witness  to  the  number  of  revolutions.  For 
this  purpose  an  electric  indicator  is  preferable.  To  meet  these 
demands  No.  618  is  offered.  This  style  of  meter  is  adapted  to 
channels  of  small  depth  and  has  a  metal  base  on  the  yoke  which 
prevents  the  meter  sinking  into  the  bed  of  the  stream. 

Suspension  is  made  by  a  graduated  tube  which  is  screwed 
into  the  frame,  permitting  the  meter  to  be  held  by  the  observer. 


FIG.  4. —  No.  618  Electric  Current  Meter,  with  base ;  also  telephone  sounder, 
cable  and  dry  cell  battery. 
Indicating  each  revolution. 


CURRENT    METERS 


23 


This  meter  indicates  each  single  revolution  of  the  bucket 
wheel  electrically  by  a  telephone  sounder. 

All  other  Gurley  meters  of  the  electric  indicating  type 
may  be  equipped  for  use  on  rods.  (See  Meters  Nos.  623  and 
624,  pages  24  and  25.) 

For  work  that  requires  thfe  meter  to  be  suspended  by  means 
of  a  meter  cord  or  cable,  two  types  are  offered.  Of  these  the 


FIG.    5. —  No.    617    Electric   Current 

Meter,  with  telephone  sounder,  cable, 

dry  cell  battery,    and    lead    weight. 

Indicating  each  revolution. 


FIG.    6. —  No.    621    Electric   Current 

Meter,  with  telephone  sounder,  cable, 

dry  cell  battery,    and    lead   weight. 

Indicating  each  fifth  revolution. 


contact  chamber  of  No.  617  is  arranged  to  indicate  each  single 
revolution  of  the  cups,  while  the  contact  chamber  of  No.  621 
indicates  each  fifth  revolution  of  the  cups. 

These  meters  are  suspended  in  use  by  a  wire  or  cable 
attached  to  the  steel  weight  hanger  which,  after  passing  through 
the  frame,  suspends  the  torpedo-shaped  weight  necessary  to 
hold  the  meter  in  the  vertical  plane  against  the  current. 

A  tail,  consisting  of  a  stem  to  which  are  fastened  two 
vanes  (separable  in  packing),  is  attached  to  the  frame  opposite 
the  bucket  wheel  and  serves  the  double  purpose  of  balancing 
the  bucket  wheel  and  keeping  the  meter  parallel  to  the  direction 
of  the  current. 


24 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


All  of  the  advantages  of  the  preceding  types  are  combined 
in  Meter  No.  623,  which  is  adapted  for  more  universal  service 
than  any  of  the  other  patterns,  as  it  can  be  used  for  measuring 
both  low  and  high  velocities,  and  can  be  suspended  by  means 
of  a  cable  or  by  a  jointed  wading  rod. 


pIG.   -4> — NO.  623  Electric  Current  Meter, 
suspended  by  cable ;  with  telephone  sound- 
er,   dry    cell    battery,    lead    weight    and 
extra  commutator  box. 
Indicating  each,  or  each  fifth,  revolution. 


FIG.  8. —  No.  623  Electric  Current  Meter, 
suspended  by  a  jointed  wading  rod,  with 
telephone  sounder,  cable,  dry  cell  battery, 
and  extra  commutator  box. 
Indicating  each,  or  each  fifth,  revolution. 

The  combination  of  these  features  provides  an  outfit  which 
has  been  adopted  as  standard  by  the  most  efficient  hydraulic 
engineers.  This  meter  is  used  extensively  by  the  Water  Re- 
sources Branch  of  the  United  States  Geological  Survey,  the 


CURRENT    METERS 25 

leading  organization  devoted  to  the  precise  measurement  of 
water. 

Two  contact  chambers,  one  to  indicate  each  revolution, 
the  other  each  fifth  revolution  of  the  bucket  wheel,  are  provided. 
These  contact  chambers  may  readily  be  interchanged,  the  only 
change  being  in  the*shaft  arid  consisting  of  the  insertion  on 
the  end  of  the  bucket  shaft  of  a  cam  when  a  single  revolution 
is  to  be  indicated,  or  of  a  worm  when  it  is  desired  to  indicate 
every  fifth  revolution. 

A  screw  socket  is  provided  on  the  frame  of  the  meter  to 
receive  a  series  of  graduated  rods  by  which  the  meter  may  be 
suspended,  if  desired,  instead  of  by  a  cable,  no  change  being 
made  in  the  meter  except  the  removal  of  the  weight  stem. 
This  modification,  the  idea  of  Mr.  C.  C.  Covert,  of  the  United 
States  Geological  Survey,  is  named  after  its  designer,  the  Covert 
Yoke.  Meter  No.  623  thus  combines  Meters  Nos.  617,  618 
and  621. 

If  the  Covert  Yoke  is  not  wanted,  Meter  No.  623 

can  be  furnished  with  a  yoke  or  frame  as  supplied  with 

No.  617  and  No.  621,  and  with  this  modification  the 

meter  is  listed  as  No.  624. 


FIG.  9. —  Nos.  617,  621  or  624  Current  Meter,  attached  to  a  ttush  jointed 
wading  rod  by  a  double  end  hanger. 

By  means  of  a  double  end  hanger,  Meters  No.  617,  621 
and  624  can  be  used  with  a  flush  jointed  wading  rod.  The 
hanger  holds  the  frame  and  bucket  wheel  on  one  side,  and 
the  vane  of  the  meter  on  the  other  side  of  the  rod,  as  shown  in 
Fig.  9. 


26 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


The  largest  size  Gurley  meter,  No.  600,  is  of  heavier  and 
more  substantial  construction  than  the  smaller  patterns,  as  it  is 
built  for  use  in  certain  investigations  of  large  rivers  and  harbors 
where  the  force  of  the  current  is  great  and  the  consequent  re- 
quirement is  for  an  instrument  which  will  withstand  extra- 
ordinarily hard  usage. 


FIG.  11. —  No.  609  Electric  Register. 

Electric  Register  No.  609  in  enclos- 
ed in  a  brass  case,  showing  three  dials 
under  a  glass  face.  The  larger  one 
records  each  revolution  up  to  one 
hundred,  the  smaller  one  on  the  right 
records  each  hundred  revolutions,  and 
the  one  on  the  left  records  each  thousand 
revolutions,  all  read- 
ing clockwise  as  in- 
dicated by  the  figur- 
ing. 

It  can  be  placed 

anywhere  in  the  circuit  and  each  revolu- 
tion of  the  meter  makes  a  contact  that 
actuates  an  electro-magnet  that  causes 
a  pawl  to  carry  forward  a  ratchet  wheel 
one  tooth  at  every  contact. 


FIG.  10. —  No.  600  Electric  Current  Meter,    large    size,    for    harbors    and 

rivers,  with  No.  606  Lead  Weight  and  Connections. 

Indicating  or  recording  each  revolution. 


CURRENT    METERS 


27 


All  current  meters  are  packed  in  a  wooden  box  with  lock, 
hooks  and  carrying  strap,  and  including  accessories  of  oil  can, 
wrench,  screwdriver  and  extra  pivot  bearing. 

A  special  carrying  case  of  fibre,  having  two  compartments, 
one  for  the  meter  and  the  other  for  the  lead  weight,  cable, 
sounder,  etc.,  as  sho*wn  in  Fig.  12,  can  be  furnished  at  an 
additional  price,  for  Meters  No.  617,  621,  623  or  624. 


FIG.  12. —  Special  Fibre  Carrying  Case  for  Current  Meters. 

Meters  are  ordinarily  supported  on  either  graduated  rods 
or  on  meter  cables.  Standard  graduated  rods  are  best  adapted 
to  low  velocities  and  to  depths  not  exceeding  five  feet.  For  high 
velocities  or  greater  depths  it  is  necessary  to  use  rods  of  special 
design. 

The  cable  must  be  strong  enough  to  properly  support  the 
amount  of  weight  used,  to  hold  the  meter  in  place.  It  must  also 
be  water-proof  and  of  high  quality.  The  cable  usually  con- 
sists of  No.  16  old  code  double  insulated  show  window  cord, 
which  will  properly  support  the  weights  generally  used.  For 
those  exceptional  cases  where  heavy  weight  is  required,  an  ap- 
propriate increase  should  be  made  in  the  size  of  the  cable. 

The  amount  of  weight  to  be  used  depends  on  the  velocity 
of  the  current  to  be  measured.  A  single  fifteen  pound  weight 


28  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

will  serve  for  the  measurement  of  ordinary  velocities.  Thirty 
pounds  weight  is  sufficient  for  all  cases  of  ordinary  practice. 
A  single  thirty  pound  weight  is  preferable,  but  for  convenience 
in  handling  two  fifteen  pound  weights  may  be  used.  When 
more  weight  is  used  it  should  be  in  one  piece  and  when  placed 
on  the  hanger  the  top  of  the  weight  should  be  not  less  than  six 
inches  from  the  bottom  of  the  cups. 

The  frequency  with  which  the  revolution  of  the  cups  will 
be  indicated  depends  on  the  velocity  of  the  water  to  be  meas- 
ured. For  velocities  under  four  feet  per  second  the  contact 
indicating  each  single  revolution  should  be  selected,  but  for 
higher  velocities  the  contact  indicating  every  fifth  revolution 
should  be  used.  Electric  Register  No.  609  will  record  satis- 
factorily all  usual  velocities  with  either  style  of  contact  chamber. 


ADVANTAGES  OF  GURLEY  CURRENT  METERS 

Reliability  in  service.  These  instruments  have  been  de- 
veloped to  meet  the  exacting  requirements  of  field  service.  The 
details  of  construction  have  been  improved  from  time  to  time 
to  insure  continuous  reliability  under  actual  working  conditions. 
They  may  be  depended  upon  to  give  accurate  results  under  try- 
ing conditions. 

Simplicity  of  design.  The  details  of  design  are  extremely 
simple.  The  instrument  is  self-contained.  There  are  no  deli- 
cate adjustments  required,  nor  are  there  any  exposed  parts  to 
give  trouble. 

Rigidity  of  construction.  Gurley  meters  are  strongly 
constructed.  They  will  resist  successfully  all  of  the  stresses 
and  shocks  incident  to  travel  and  field  service. 

Adaptability.  Gurley  meters  are  equally  well  adapted  to 
the  measurement  of  small  streams  and  large  rivers.  A  single 
meter  may  be  used  on  both  classes  of  work  by  simply  altering 
the  method  of  suspension. 

Size.  The  compactness  of  the  Gurley  meter  is  a  material 
advantage.  It  can  be  packed  when  traveling  in  a  box  small 
enough  to  be  carried  in  a  hand  bag.  Its  size  is  also  an  advantage 
in  handling  when  in  actual  use. 


CURRENT    METERS  29 

COMPLETE  CURRENT  METER  FIELD  OUTFIT 

A  complete  current  meter  outfit  for  field  use  consists  of: 

(1)  Meter  itself,  with  ils  rating  table. 

(2)  Telephone  or  othen  indicating  device,  connected  up 

with  insulated  wire  in  circuit  with  dry  cell  and 
connecting  plugs,  ready  for  use. 

(3)  Oil  can,  filled  with  clock  oil. 

(4)  Small  screw  driver. 

(5)  Spanner  wrench  for  dismantling  the  meter. 

(6)  Cable  for  supporting  the  meter,  equipped  with  snap. 

(7)  Torpedo  weights. 

(8)  Hanger. 

(9)  Hanger  screw. 

(10)  Stopwatch. 

(11)  Rods  for  wading  measurements. 

(12)  Notebook,  containing  blueprint  of  rating  table  for 

the  meter  used,  a  list  of  special  tools,  equipment, 
and  also  clothing,  to  be  carried  if  the  trip  is  to 
be  an  extended  one. 

The  Notebook  should  also  contain  a  supply  of  note  forms, 
including 

Discharge  Measurement  General  Data,  Form  No.  H-325 

(See  page  54). 

Current  Meter  Notes,  Form  No.  H-326  (See  page  55). 
Current  Meter  Notes — Ice  Cover,  Form  No.  H-327  (See 

page  60). 

Inspection  of  Recording  Register  Stations  (See  page  127). 
Level  Notes. 
Sketch  Sheets. 

It  will  be  convenient  to  be  supplied  with  the  following 
articles,  which  are  frequently  necessary  or  desirable  for  mak- 
ing repairs  to  the  station  equipment  and  for  the  ordinary  oper- 
ation of  the  current  meter: 

( 1 )  Parallel  pliers  with  wire  cutter. 

(2)  Bottle  of  special  clock  oil,  which  will  not  clog  in  cold 

weather. 

(3)  Roll  of  adhesive  tape. 

(4)  25-foot  metallic  tape. 


30          W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

(5)  50-foot  steel  tape. 

(6)  Extra  pivot  point. 

(7)  Extra  set  of  screws,  for  meter. 

(8)  Extra  screws,  for  hanger. 

(9)  Extra  battery,  with  binding  posts  wound  with  insul- 

ating tape. 

(10)  Extra  contact  spring  in  rubber  bushing. 

(11)  Insulating  wire. 

(12)  Small  hatchet. 

(13)  Assortment   of  nails.      Piece   of  twine.      Piece  of 

cotton  cloth,  for  drying  meter. 


CARE  OF  THE  CURRENT  METER 

TO  TAKE  THE  METER  APART 

When  taking  the  meter  apart,  remove  the  tail  vanes  and  the 
hanger  stem;  then  loosen  the  set-screw  to  the  contact  chamber, 
and  pull  the  chamber  out  by  a  slight  twisting  motion.  Care 
must  be  taken  to  let  the  cups  be  free  to  turn,  so  that  the  worm 
gear  on  the  upper  end  of  the  shaft  can  disengage  from  the 
teeth  of  the  contact  wheel.  In  handling  the  contact  chamber, 
it  is  well  to  take  off  the  cap,  so  that  the  gear-wheel  can  be  seen 
during  the  operation.  The  pivot-point  can  then  be  taken  out 
and  the  cups  released  by  loosening  the  upper  part  of  the  shaft 
with  a  spanner  wrench.  This  wrench  is  so  designed  that  it  can 
be  used  for  loosening  all  parts  of  the  meter. 

In  putting  the  meter  together,  first  attach  the  cups  to  the 
cup  shaft.  In  doing  this,  the  upper  part  of  the  shaft  should 
be  inserted  through  the  upper  hole  of  the  yoke  before  it  is 
screwed  to  the  lower  part.  Care  must  be  taken  to  place  the 
cups  so  that  they  will  move  counter-clockwise.  After  the  cups 
have  been  fastened  to  the  shaft,  insert  the  pivot  point  and  clamp 
it  in  place,  and  then  insert  the  contact  chamber.  In  replacing 
the  contact  chamber,  the  cups  should  be  left  free  to  move  on 
the  pivot  point.  Before  inserting  the  frame  nut,  the  pivot  point 
should  be  adjusted  and  firmly  secured  with  the  lock-nut.  The 
adjustment  should  allow  a  slight  vertical  motion  of  the  cups. 


CURRENT    METERS 31 

TO  CHANGE  CONTACT  CHAMBERS 

1.  Loosen  the  set  screw  to  the  contact  chamber  in  place. 

2.  Carefully  lift  the  contact  chamber  from  the  yoke. 

3.  Carefully  unscrew  either  the  worm,  or  eccentric,  from 
the  shaft  and  screw  in  -the  othei%  which  will  be  found  in  the  small 
round  tin  box. 

4.  Slide  back  in  place  the  other  chamber,  which  is  in  a 
block  in  one  corner  of  the  meter  box,  and  tighten  the  set  screw. 

SPECIAL  INSTRUCTIONS 

Although  the  current  meter  is  substantially  made,  and 
will  stand  considerable  hard  usage,  it  needs  careful  handling 
and  attention  to  insure  its  proper  working.  In  this  connection 
the  following  instructions  should  be  carefully  observed: 

1.  Be  sure  that  the  set-screws  are  all  tightened  before 
putting  the  meter  in  the  water;  otherwise,  some  of  the  parts 
may  be  lost. 

2.  Loosen  the  raising  nut  and  see  that  the  meter  runs 
freely  before  beginning  a  measurement.     Spin  the  meter  cups 
occasionally  during  a  measurement  to  see  that  they  are  run- 
ning freely,  that  is,  that  they  will  continue  to  move  for  a  con- 
siderable time  at  a  slow  velocity. 

3.  See  that  the  weights  play  freely  on  the  stem,  so  as 
to  take  the  direction  of  the  current  and  thus  avoid  an  unneces- 
sary drag  on  the  line. 

4.  If  any  apparent  inconsistency  in  the  results  of  an 
observation    throws    doubt    on    its    accuracy,    investigate    the 
cause  at  once.    Grass  may  be  wound  around  the  cup  shaft;  the 
cups  may  be  tilted  by  tension  on  the  contact  wire;  the  channel 
may  be  obstructed  immediately  above  the  meter;  the  meter 
may  be  in  a  hole;  or  the  cups  may  be  bent  so  as  to  come  in 
contact  with  the  yoke. 

5.  After  a  measurement,  it  is  absolutely  necessary  to 
pour  out  any  water  that  may  have  collected  in  the  commutator 
box,  to  clean  and  oil  the  bearings  (in  order  to  prevent  rust) 
and  to  inspect  the  pivot  point. 

6.  When  the  meter  is  not  in  use,  the  cups  should  never 
be  permitted  to  ride  on  the  pivot  point. 


32  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

7.  Always  see  that  the  lock-nut  on  the  pivot-point  is 
screwed  firmly  against  the  frame  nut,  so  that  it  will  stay  in 
place  and  carry  the  cups  properly. 

8.  Never  use  a  dulled  pivot.    Always  keep  several  extra 
pivots  on  hand. 

9.  In  measuring  low  velocities,  be  sure  that  the  meter 
is  in  a  horizontal  position.     If  it  has  a  tendency  to  tip,    the 
balance  weight  on  the  tail  should  be  adjusted  or  the  meter  be 
held  rigidly  by  inserting  a  plug  in  the  slot  against  the  stem. 

10.  Avoid  taking  measurements  in  velocities    of    less 
than  0.5  foot  per  second,  because  the  accuracy  of  the  meter 
diminishes  as  zero  velocity  is  approached. 

11.  For  velocities  of  less  than  1  foot  per  second,  the 
pivot  point  should  be  the  same  as  at  the  time  of  rating,  sharp 
and  smooth.     As  the  velocity  increases,  the  condition  of  the 
point  is  less  important,  because  the  friction  factor  decreases. 

12.  In  taking  measurements  at  high  velocities,  sufficient 
weight,  and  a  stay-line,  should  be  used  to  hold  the  meter  in  a 
vertical  position. 

13.  In    very    shallow 
streams  the  meter    should   be 
suspended  from  the  lower  hole 
on   the    stem,  and  the  weight 

should  be  placed  above.  FlG  13 

14.  If  the  cups  of  the 
meter  are   bent,  they  may  be 
easily  put  in  shape  by  pressing 
them  with  a  piece  of  wood  or 

metal    with    a    round,    smooth  FlG  14 

end. 

15.  The    telephone    re- 
ceiver is  very  sensitive  to  elec- 
tric currents,  and  can  be  used 

to  locate  any  break  in  the  circuit. 

_.  111'  ii  -^  ^*  •"*• 

r  irst  try  the  telephone  and  bat-  m    ,.      _,  .      „.      .. 

*  .        ,_.*    ,  ON  .  .  Testing  Meter  Circuit. 

tery  together  (rig.  lo)  m  a  cir- 
cuit having  a  make-and-break  point,  as  at  a.     This    may    be 
done  by  using  a  knife  blade  or  a  screw  driver,  making  con- 
nection where  the  wires  enter  the  plug.     If  there  is  no  click  in 


CURRENTMETERS 


33 


the  telephone,  then  the  battery  or  the  telephone  does  not  make 
a  circuit.  If  there  is  a  click,  insert  the  meter  in  the  line  and 
test  for  a  contact  in  the  meter  head  (Fig.  14)  by  revolving  the 
meter  wheel.  If  the  meter  is  all  right,  put  the  meter  cord  in 
the  circuit  and  test  both  sides  either  by  inserting  a  fine  needle 
that  joins  both  conductors  or  b^  making  double  connection  and 
touching  alternate  sides  of  the  line,  a.  (Fig.  15). 

16.  When  the  meter  is  not  in  use,  disconnect  the  meter 
line  from  the  battery,  so  that  it  will  not  become  exhausted. 

17.  Do  not  strike  the  telephone  receiver,  as  a  heavy  jar 
will  to  a  greater  or  less  extent,  damagnetize  the   pole    pieces, 
and  to  that  extent  will  injure  the  receiver.     If  care  is  taken,  it 
is  very  improbable  that  the  telephone  receiver  will  get  out  of 
order. 

18.  Care  must  be  taken    not    to    short-circuit    the    dry 
battery  when  the  meter  is  not  in  use.    To  avoid  this,  the  poles 
may  be  wound  with  adhesive  tape. 

RATING  THE  CURRENT  METER 

The  relation  between  the  revolutions  of  the  meter  cups 
and  the  velocity  of  the  water  may  be  determined  by  rating 
each  meter  before  it  is  used.  Theoretically,  the  rating  for  all 
meters  of  the  same  make  should  be  the  same,  but,  as  a  result 


FIG.  16. —  Current  Meter  Rating  Station  at  U.  S.  Bureau  of  Standards. 


34 


W.  &  L.  E.  G  U  R  L  E  Y,  TROY,  N.  Y. 


of  slight  variations  in  construction,  and  in  the  bearing  of  the 
wheel  on  the  axis  at  different  velocities,  the  ratings  differ 
slightly. 

A  meter  is  rated  by  moving  it  through  still  water  with 
uniform  speed,  and  noting  the  time,  the  number  of  revolutions, 
and  the  distance  (Figs.  16  and  17).  The  revolutions  per  second 
and  the  velocity  in  feet  per  second  are  afterward  cpmputed 
from  these  data.  Many  runs  are  made,  the  speeds  varying 
from  the  least  which  will  cause  the  wheel  to  revolve  to  several 
feet  per  second.  The  results  of  these  runs,  when  plotted  with 
revolutions  per  second  and  velocity  in  feet  per  second  as 
co-ordinates,  locate  the  points  which  define  the  meter  rating 
curve  from  which  the  rating  table  is  prepared. 

The  number  of  revolutions  of  the  meter  wheel  are  indi- 
cated on  an  electric  recorder;  the  distance  is  obtained  by  an 
electrical  mechanism,  which  is  in  circuit  with  the  meter  wheel, 
so  that  the  exact  distance  for  a  given  number  of  revolutions  is 
obtained;  and  the  time  is  taken  by  a  chronograph  or  a  stop- 
watch, which  is  started  and  stopped  by  means  of  an  electrical 
control. 

Long  experience  has  shown  that  with  good  care  meters 
do  not  readily  lose  their  adjustment.  When  used  carefully, 
every  day,  in  ordinary  service,  a  meter  should  be  rated  once 
in  three  months  as  a  check.  Meters  in  similar  service,  but  used 
less  frequently,  should  be  rated  once  a  year  as  a  check.  For 


FIG.  17. —  Current  Meter  Rating  Station  of  Irrigation  Branch, 
Canadian  Interior  Department. 


CURRENT    METERS 35 

special  work  the  meter  should  be  rated  before  beginning  and 
as  frequently  as  may  be  necessary  during  the  work. 

The  details  of  rating  a  current  meter  and  of  preparing  the 
meter  rating  curve  and  table  are  given  in  "River  Discharge."* 
The  rating  should  be  done  at  abating  station,  properly  equipped 
to  carry  on  the  work!  The  rating  station  should  be  allowed 
ample  time,  usually  about  two  weeks,  to  make  the  rating  and  to 
compute  the  rating  table.  The  following  table  gives  a  list  of 
rating  stations  and  the  cost  of  rating  a  meter: 

STATION  ADDRESS  RATING  FEE 

U.  S.  Bureau  of  Standards,  Washington,  D.  C.     $10  for  each  head 

Rensselaer  Polytechnic  Institute,    Troy,  N.  Y.  $10    "     "        " 

Worcester  Polytechnic  Institute,     Worcester,  Mass. 
Cornell  University,  Ithaca,  N.  Y. 

University  of  Michigan, 

Naval  Tank,   Ann  Arbor,  Mich. 
Imperial  Valley  Development  Co.,  Calexico,  Cal. 
University  of  Toronto,  Toronto,  Ontario. 

Irrigation  Branch,  Department 

of  the  Interior,   Calgary,  Alberta. 

Theoretically,  the  wheel  of  a  differential-action  meter, 
when  carried  through  still  water,  should  revolve  as  a  wheel 
revolves  in  passing  over  the  ground.  That  is,  in  going  a  given 
distance  it  should  make  practically  the  same  number  of  revo- 
lutions, regardless  of  speed.  The  rating  of  a  great  many  small 
Gurley  electric  meters  shows  this  number  to  be  from  42  to  44 
revolutions  in  going  100  ft. 

The  true  number  of  revolutions  of  the  wheel  should  equal 
the  distance  of  the  run  divided  by  the  effective  circumference 
of  the  wheel  multiplied  by  a  coefficient  which  depends  on  the 
retarding  effect  due  to  the  pressure  on  the  convex  surface  of  the 
cups  and  their  blanketing  effect.  Assuming  the  effective  cir- 
cumference to  be  the  circle  passing  through  the  points  of  the 
cups,  which  is  0.7854  ft.,  and  the  true  number  of  revolutions 
to  be  43%  per  100  ft.  run;  then  the  coefficient  would  be  0.345. 
Although  complete  data  are  not  available  to  confirm  this 
theory,  the  working  of  the  meter  shows  that  it  holds  very  closely 
to  it. 

The  foregoing  shows  that  the  theoretical  meter-rating 
curve  is  a  straight  line  passing  through  the  origin.  If  the  true 
number  of  revolutions  made  in  going  100  ft.  is  43%,  the 

*"  River  Discharge",  by  Hoyt  and  Orover,  for  sale  by  W.  &  L.  B. 
Gurley,  price  $2.00,  postpaid. 


36 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


equation  of  this  curve  will  be  X  =  2.3  Y,  where  X  =  velocity, 
in  feet  per  second,  and  Y  =  revolutions  per  second. 

A  study  of  the  rating  curves  of  a  large  number  of  small 
Gurley  meters  shows  that,  as  a  rule,  the  curve  is  made  up  of  two 
straight  lines,  the  extension  of  the  lower  one  joining  the  upper 
one  in  an  angle  between  the  velocities  of  8  and  9  ft.  At  this 
point  there  is  a  slight  increase  in  the  friction  on  the  bearings 
of  the  meter  wheel  and  shaft.  Notwithstanding  this  break  in 
the  curve,  the  observed  curve  parallels  the  theoretical  curve 
very  closely.  The  lower  part  of  the  curve  starts  at  a  velocity 
of  less  than  0.1  ft.  per  second,  which  is  required  to  start  the 
wheel. 

In  using  the  meter,  observation  is  made  of  the  number  of 
seconds  the  wheel  requires  to  make  a  selected  number  of  revo- 
lutions. Therefore,  a  rating  table  is  prepared  for  each  meter, 
giving  the  velocities  per  second  corresponding  to  the  number 
of  revolutions.  The  most  convenient  table  is  prepared  for  5, 
10,  20,  30,  40,  50,  60,  70,  80,  90,  100,  150,  and  200  revo- 
lutions, with  the  times  of  the  runs  ranging  from  40  to  70  seconds, 
giving  velocities  from  0.19  to  11.12  feet  per  second. 
Reduction  Table  for  Use  with 

Acoustic  Current  Meter,  No.  616 

This  Table  is  a  mean  of  the  ratings  of  many  different  meters,  and  will  probably  give 
correct  values  within  one  per  cent,  for  any  meter  of  its  pattern  when  in  good  order. 

The  time  column  is  the  number  of  seconds  that  have  elapsed  during  one  hundred 
revolutions  of  the  wheel,  there  being  ten  revolutions  to  each  rap. 


Time 

Velocity 

Time 

Velocity 

Time 

Velocity 

Time 

Velocity 

1000 

0.27 

111 

2.11 

59 

3.96 

37 

6.28 

666 

.39 

105 

2.22 

57 

4.08 

36 

6.51 

500 

.50 

100 

2.34 

56 

4.20 

34 

6.74 

400 

.61 

95 

2.46 

54 

4.31 

33 

6.98 

333 

.72 

91 

2.57 

53 

4.43 

32 

7.21 

286 

.83 

87 

2.69 

51 

4.54 

31 

7.44 

250 

.95 

83 

2.80 

50 

4.66 

30 

7.67 

222 

1.07 

80 

2.92 

49 

4.78 

29 

7.91 

200 

1.18 

77 

3.03 

48 

4.90 

28 

8.25 

182 

1.30 

74 

3.15 

46 

5.01 

27 

8.48 

167 

1.42 

71 

3.26 

45 

5.12 

26 

8.83 

154 

1.53 

69 

3.38 

44 

5.24 

25 

9.29 

143 

1.65 

67 

3.50 

43 

5.35 

24 

9.64 

133 

1.77 

65 

3.61 

42 

5.58 

23 

10.10 

125 

1.88 

62 

3.73 

40 

5.82 

22 

10.56 

118 

1.99 

61 

3.85 

38 

6.05 

21 

11.02 

CURRENT    METERS 


37 


Reduction  Table  for  Use  with 

Electric  Current  Meters,  Nos.  617,  618, 
621,  623  and  624 

This  Table  is  based  on  the- ratings  of  many  meters.  The  comparisons  of  the  ratings 
of  meters  Nos.  617,  618,  621,  623  and  624,  both  penta  recording  and  single  point  contact, 
show  an  agreement  with  this  table  within  one  per  cent.  Occasional  ratings  vary  more 
than  one  per  cent.,  when  an  individual  rating  table  may  be  prepared. 

[Extract  from  instructions  given  by  the  Water  Resources  Branch  of  the  United 
States  Geological  Survey  to  their  Hydraulic  Engineers.] 


VELOCITY  IN  FEET  PER  SECOND 

Time 

Time 

in 

in 

Seconds 

5 

10 

20 

30 

40 

50 

60 

70 

80 

90 

100 

150 

200 

Seconds 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

40 

0.31 

0.58 

1.13 

.68 

2.23 

2.78 

3.34 

3.90 

4.45 

5.01 

5.56 

8.34 

11.12 

40 

41 

0.30 

0.57 

1.10 

.64 

2.18 

2.71 

3.26 

3.81 

4.34 

489 

5.43 

8.14 

10.85 

41 

42 

0.30 

0.56 

1.07 

.60 

2.13 

2.65 

3.18 

3.72 

4.24 

4.77 

5.30 

7.95 

10.59 

42 

43 

0.29 

0.54 

1.05 

.56 

2.08 

2.59 

3.11 

3.63 

4.14 

4.66 

5.18 

7.77 

10.34 

43 

44 

0.28 

0.53 

1.03 

.53 

2.03 

2.53 

3.04 

3.55 

4.04 

4.55 

5.06 

7.59 

10.10 

44 

45 

0.28 

0.52 

1.01 

.50 

1.99 

2.48 

2.97 

3.47 

3.95 

4.45 

4.95 

7.42 

9.87 

45 

46 

0.28 

0.51 

0.99 

.47 

1.95 

2.43 

2.90 

3.39 

3.87 

4.35 

4.84 

7.26 

9.65 

46 

47 

0.27 

0.50 

0.97 

1.44 

1.91 

2.38 

2.84 

3.32 

3.79 

4.26 

4.74 

7.11 

9.45 

47 

48 

0.26 

0.49 

0.95 

1.41 

1.87 

2.33 

2.78 

3.25 

3.71 

4.17 

4.64 

6.96 

9.25 

48 

49 

0.26 

0.48 

0.93 

1.38 

1.83 

2.28 

2.72 

3.18 

3.63 

4.09 

4.54 

6.81 

9.06 

49 

50 

0.26 

0.47 

0.91 

1.35 

1.79 

2.23 

2.67 

3.12 

3.56 

4.01 

4.45 

6.67 

8.89 

50 

51 

0.25 

0.46 

0.90 

1.32 

1.75 

2.19 

2.62 

3.06 

3.49 

3.93 

4.36 

6.54 

8.72 

51 

52 

0.25 

0.46 

0.88 

1.29 

1.72 

2.15 

2.57 

3.00 

3.42 

3.85 

4.28 

6.42 

8.56 

52 

53 

0.24 

0.45 

0.86 

1.27 

1.69 

2.11 

2.52 

2.94 

3.36 

3.78 

4.20 

6.30 

8.40 

53 

54 

0.24 

0.44 

0.85 

1.25 

1.66 

2.07 

2.47 

2.88 

3.30 

3.71 

4.12 

6.18 

8.24 

54 

55 

0.24 

0.43 

0.83 

1.23 

1.63 

2.03 

2.43 

2.83 

3.24 

3.64 

4.05 

6.07 

8.09 

55 

56 

0.23 

0.43 

0.82 

1.21 

1.60 

1.99 

2.39 

2.78 

3.18 

3.58 

3.98 

5.96 

7.95 

56 

57 

0.23 

0.42 

0.80 

1.19 

1.57 

1.96 

2.35 

2.73 

3.12 

3.52 

3.91 

5.86 

7.81 

57 

58 

0.22 

0.41 

0.79 

1.17 

1.54 

1.93 

2.31 

2.68 

3.07 

3.46 

3.84 

5.76 

7.68 

58 

59 

0.22 

0.41 

0.78 

1.15 

1.51 

1.90 

2.27 

2.63 

3.02 

3.40 

3.77 

5.66 

7.55 

59 

60 

0.22 

0.40 

0.77 

.13 

1.48 

1.87 

2.23 

2.59 

2.97 

3.34 

3.71 

5.56 

7.42 

60 

61 

0.22 

0.39 

0.75 

.11 

1.46 

1.84 

2.19 

2.55 

2.92 

3.29 

3.65 

5.47 

7.30 

61 

62 

0.21 

0.39 

0.74 

.09 

1.44 

1.81 

2.16 

2.51 

2.87 

3.24 

3.59 

5.38 

7.18 

62 

63 

0.21 

0.38 

0.73 

.07 

1.42 

1.78 

2.13 

2.47 

2.82 

3.19 

3.53 

5.30 

7.07 

63 

64 

0.21 

038 

0.72 

.05 

1.40 

1.75 

2.10 

2.43 

2.77 

3.14 

3.48 

5.22 

6.96 

64 

65 

0.20 

0.37 

0.71 

.03 

1.38 

1.72 

2.07 

2.39 

2.73 

3.09 

3.43 

5.14 

6.85 

65 

66 

0.20 

0.37 

0.70 

.02 

1.36 

1.69 

2.04 

2.35 

2.69 

3.04 

3.38 

5.06 

6.75 

66 

67 

0.20 

0.36 

0.69 

.01 

1.34 

1.66 

2.01 

2.32 

2.65 

2.99 

3.33 

4.98 

6.65 

67 

68 

0.20 

0.36 

0.68 

.00 

1.32 

1.64 

1.98 

£.29 

2.61 

2.95 

3.28 

4.91 

6.55 

68 

69 

0.19 

0.35 

0.67 

0.99 

1.30 

1.62 

1.95 

2.26 

2.57 

2.91 

3.23 

4.84 

6.45 

69 

70 

0.19 

0.35 

0.66 

0.98 

1.28 

1.60 

1.92 

2.23 

2.53 

2.87 

3.18 

4.77 

6.36 

70 

38 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


Reduction  Table  for  Use  with 

Electric  Current  Meter,  No.  600 

This  Table  is  a  mean  of  the  ratings  of  many  different  meters  and  will  probably  give 
correct  values  within  one  per  cent,  for  any  meter  of  its  pattern  in  good  order. 

The  observations  of  time  should  be  made  with  a  stop-watch  and  taken  to  a  fraction 
of  a  second. 


I 

VEL( 

5CITY 

IN  FE 

;ET  PE 

:R  SEC 

:OND 

3 

.s 

£ 

n 

V 

i 

5 

10 

20 

30 

40 

50 

60 

70 

80 

90 

100 

105 

g 

H 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

Revs. 

H 

40 

0.555 

0.950 

1.74 

2.53 

3.32 

4.11 

4.89 

5.60 

6.34 

7.07 

7.81 

11.48 

40 

41 

0.545 

0.930 

1.70 

2.48 

3.24 

4.01 

4.77 

5.48 

6.19 

6.91 

7.63 

11.21 

41 

42 

0.536 

0.912 

1.66 

2.43 

3.17 

3.92 

4.66 

5.37 

6.05 

6.75 

7.46 

10.95 

42 

43 

0.527 

0.894 

1.63 

2.37 

3.10 

3.84 

4.56 

5.25 

5.93 

6.62 

7.29 

10.73 

43 

44 

0.518 

0.877 

1.60 

2.32 

3.03 

3.76 

4.46 

5.13 

5.81 

6.49 

7.13 

10.48 

44 

45 

0.509 

0.861 

1.56 

2.27 

2.97 

3.68 

4.37 

5.03 

5.68 

6.36 

6.98 

10.26 

45 

46 

0.501 

0.846 

1.53 

2.22 

2.91 

3.60 

4.28 

4.93 

5.57 

6.22 

6.84 

10.04 

46 

47 

0.495 

0.831 

1.50 

2.17 

2.85 

3.52 

4.20 

4.84 

5.47 

6.10 

6.71 

9.83 

47 

48 

0.488 

0.817 

1.48 

2.13 

2.79 

3.45 

4.13 

4.75 

5.37 

5.98 

6.59 

9.63 

48 

49 

0.482 

0.804 

1.45 

2.09 

2.74 

3.38 

4.04 

4.66 

5.26 

5.86 

6.48 

9.45 

49 

50 

0.476 

0.792 

1.42 

2.06 

2.69 

3.32 

3.95 

4.58 

5.16 

5.75 

6.36 

9.28 

50 

51 

0.469 

0.782 

1.40 

2.03 

2.64 

3.26 

3.87 

4.50 

5.07 

5.65 

6.23 

9.10 

51 

52 

0.463 

0.763 

1.38 

2.00 

2.59 

3.20 

3.79 

4.43 

4.99 

5.55 

6.11 

8.93 

52 

53 

0.457 

0  753 

1.35 

1.96 

2.54 

3.14 

3.73 

4.35 

4.90 

5.46 

6.00 

8.78 

53 

54 

0.453 

0.744 

1.33 

1.92 

2.50 

3.09 

3.67 

4.28 

4.81 

5.37 

5.90 

8.63 

54 

55 

0.448 

0.735 

1.31 

1.88 

2.46 

3.03 

3.60 

4.20 

4.73 

5.28 

5.81 

8.58 

55 

56 

0.443 

0.726 

.29 

1.85 

2.42 

2.98 

3.54 

4.13 

4.65 

5.19 

5.72 

8.34 

56 

57 

0.438 

0.715 

.27 

1.82 

2.38 

2.93 

3.47 

4.05 

4.58 

5.10 

5.62 

8.20 

57 

58 

0.433 

0.705 

.25 

1.79 

2.34 

2.88 

3.41 

3.98 

4.51 

5.02 

5.52 

8.07 

58 

59 

0.427 

0.696 

.22 

1.76 

2.30 

2.83 

3.36 

3.92 

4.44 

4.95 

5.44 

7.94 

59 

60 

0.423 

0.687 

.21 

1.74 

2.27 

2.79 

3.32 

3.86 

4.37 

4.89 

5.37 

7.81 

60 

61 

0.419 

0.678 

.19 

1.71 

2.23 

2.75 

3.27 

3.79 

4.31 

4.80 

5.28 

7.69 

61 

62 

0.416 

0.669 

.18 

1.69 

2.20 

2.71 

3.22 

3.73 

4.25 

4.72 

5.19 

7.57 

62 

63 

0.413 

0.661 

.16 

1.66 

2.16 

2.67 

3.17 

3.66 

4.19 

4.67 

5.12 

7.45 

63 

64 

0.410 

0.653 

.15 

1.64 

2.13 

2.63 

3.13 

3.60 

4.13 

4.58 

5.05 

7.34 

64 

65 

0.405 

0.646 

.13 

1.61 

2.10 

2.59 

3.09 

3.55 

4.05 

4.52 

4.97 

7.23 

65 

66 

0.401 

0.639 

.12 

1.59 

2.07 

2.55 

3.04 

3.51 

3.98 

4.46 

4.90 

7.13 

66 

67 

0.397 

0.632 

.10 

1.57 

2.04 

2.51 

2.99 

3.46 

3.92 

4.40 

4.84 

7.03 

67 

68 

0.392 

0.625 

.09 

1.55 

2.02 

2.48 

2.95 

3.41 

3.86 

4.34 

4.78 

6.94 

68 

69 

0.388 

0.618 

.07 

1.53 

1.99 

2.45 

2.91 

3.36 

3.81 

4.29 

4.72 

6.85 

69 

70 

0.384 

0.612 

1.06 

1.51 

1.96 

2.42 

2.88 

3.32 

3.76 

4.24 

4.66 

6.76 

70 

CURRENT    METERS 


39 


TYPES  OF  CURRENT  METER  MEASUREMENTS 

There  are  three  classes  of  current  meter  measurements 
in  common  use.  They  are  named  from  the  means  employed 
by  the  hydrographer  in  reaching  the  measuring  points,  as  fol- 
lows: wading,  cable,  #nd  bridge  measurements. 

Boat  measurements  are  occasionally  used  (Fig.  18).  The 
boats  used  for  this  work  should  be  specially  equipped  so  that 
all  influence  of  the  boat  on  the  current  measured  is  eliminated. 
Two  ordinary  boats  may  be  quickly  equipped  at  a  small  ex- 


FIG.  18. —  Boat  equipped  for  Current  Meter  Measurements. 


FIG.  19. —  Catamaran  equipped  for  Current  Meter  Measurements. 


40  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

pense  as  a  catamaran  (Fig.  19),  from  which  meters  may  be 
operated  with  great  facility,  in  other  than  flood  conditions. 
Precise  results  have  been  obtained  in  smooth  water  from  a  rig 
of  this  kind. 

All  measuring  sections  that  are  to  be  maintained  continu- 
ously should  have  a  fairly  smooth  bed,  a  uniform  velocity  of 
current  not  less  than  0.5  foot  per  second  at  any  stage,  uniformly 
distributed  throughout  the  section,  with  no  strong  eddies, 
cross  currents,  or  boils,  a  permanent  control  assuring  a 
constant  relation  between  gage  height  and  discharge,  and 
should  not  be  subject  to  marked  fluctuations  during  the 
measurements.  In  changing  conditions,  the  flow  past  the 
control  is  the  essential  factor,  because  the  records  of  gage 
height  and  the  rating  table  pertain  to  the  section  at  the 
control,  and  not  necessarily  to  the  section  in  which  the  dis- 
charge measurements  are  made.  A  permanent  reef  or  ledge 
extending  across  the  stream  (Fig.  20),  a  short  distance  below 
the  edge,  will  control  the  relation  between  gage  height  and  dis- 
charge, even  though  the  bed  of  the  measuring  section  itself 
may  change.  Where  no  natural  control  exists,  an  artificial 
control  (Fig.  21)  may  be  constructed.  In  general,  it  has  been 
found  more  economical  in  the  long  run  to  make  stream  measure- 
ments where  the  conditions  are  permanent,  even  though  the  cost 
may  be  greater  than  if  the  measurements  were  made  at  a  more 
easily  accessible  point,  but  with  changing  conditions. 


CURRENT    METERS 


41 


FIG.  20. —  Natural  Control  of  a  Stream. 


FIG.  21. —  Artificial  Control  of  a  Stream. 


42  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

WADING   MEASUREMENTS 

Measurements  are  made  by  wading  (Fig.  22),  wherever 
the  depth  and  velocity  of  the  stream  permit  the  hydrographer 
to  reach  all  measuring  points  and  to  hold  the  meter  in  position. 

To  mark  the  points  at  which  observations  are  taken,  it  is 
customary  to  stretch  a  marking  line  across  the  stream.  For  this 
purpose  a  metallic  tape  may  be  stretched  between  iron  rods 
that  have  slits  in  their  ends;  when  there  is  a  little  wind,  or  for 
lengths  not  exceeding  200  feet,  a  braided  silk  fish  line  may 
be  used.  The  line  should  be  prepared  for  such  use  by  marking 
it  off  while  well  stretched,  into  short  lengths,  say  four  feet  each, 
with  black  paint,  using  special  marks  every  20  feet.  When  put 
in  place  for  use  the  line  is  stretched  until  divisions  are  of  the 
correct  length  when  checked  with  a  steel  tape.  For  greater 
lengths  a  galvanized  telephone  wire,  or  a  twisted  smooth  fence 
wire,  may  be  used,  the  size  of  the  wire  being  properly  pro- 
portioned to  the  span. 

The  tape  or  the  fish  line  which  forms  part  of  the  hydrog- 
rapher's  kit  is  kept  stretched  across  the  stream  only  during 
the  measurement,  but  wire  markers  are  ordinarily  left  in  place 
at  the  station. 

Measurements  should  be  made  according  to  the  condition 
of  roughness  of  the  stream  bed.  Under  ordinary  conditions  the 
two-tenth  and  eight-tenth  method  should  be  used  if  the  meter 
can  be  properly  submerged  for  the  upper  measurements.  In 
shallow  water  near  the  bank  the  six- tenth  method  may  be  used. 
If  a  stream  is  very  shallow  and  its  bed  rough,  the  position  of 
the  thread  of  mean  velocity  may  rise  to  one  half  of  the  depth. 
The  hydrographer  using  the  wading  method  can  get  his  sound- 
ings accurately  and  can  set  his  meter  exactly  at  the  proper 
positions.  This  method  does  not  confine  all  measurements  to 
a  single  section,  but  permits  the  hydrographer  to  select  the  most 
suitable  section  each  time  a  measurement  is  made  and  is  es- 
pecially useful  on  small  streams  or  at  low  stages.  See  page  51. 

In  making  such  measurements,  the  engineer  should  stand 
below  the  tape  line  and  to  one  side  of  the  meter  (Fig.  23), 
in  order  that  he  may  not  disturb  its  action. 


CURRENT    METERS 


43 


FIG.  22. — Wading  Measurement. 


FIG.  23. —  Typical  Gaging  Station  for  Wading  Measurement. 


44  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


MEASUREMENTS   FROM   CABLES 

Cables  (Figs.  24,  25,  26,  27,  and  28),  afford  ready 
means  of  gaging  streams  up  to  a  thousand  feet  in  width,  which 
includes  most  cases.  The  advantage  in  using  a  cable  lies  in  the 
fact  that  the  station  may  be  placed  at  the  most  favorable 
location  independently  of  existing  structures.  Complete  details 
for  installing  cable  stations  are  given  in  (U.  S.  Geological 
Survey)  Water  Supply  Paper  No.  371. 

At  cable  stations  the  meter  is  suspended  by  means  of  the 
meter  cable  of  No.  16  old  code  double  insulated  show  window 
cord,  which  is  thick  enough  to  afford  a  comfortable  grip  and 
not  cut  the  hands.  A  piece  of  twisted  sash  cord,  or  a  specially 
prepared  meter  cord,  carrying  in  the  center  an  insulated  wire 
and  long  enough  to  reach  from  the  bottom  of  the  stream  to  the 
surface  of  the  water,  is  used  between  the  top  of  the  meter 
hanger  and  the  meter  cord  in  order  to  minimize  the  effect  of 
the  current.  (See  Fig.  1). 

In  swift  water  a  head  line  is  used  to  hold  the  meter  in  a 
vertical  position.  It  is  made  of  a  piece  of  No.  10  galvanized 
iron  wire,  long  enough  to  reach  from  the  top  of  the  meter  hanger, 
to  which  one  end  of  it  is  attached,  to  a  rope  above  the  surface. 
The  rope  is  carried  to  pulleys  on  a  stay  line  some  distance  up- 
stream, and  back  to  the  car.  The  hydrographer  adjusts  the 
stay  line  as  required.  (See  Fig.  25). 

At  cable  stations  it  is  customary  to  use  the  two-tenth  and 
eight-tenth  method,  taking  the  observation  every  5  or  10  feet, 
according  to  the  width  of  the  stream. 


FIG.  24. —  Current  Meter  Gaging  Station. 


CURRENT    METERS 


45 


FIG.  25. —  Typical  Current  Meter  Gaging  Station  with 
Automatic  Water  Stage  Register. 


FIG.  26. —  Current  Meter  Observers  in  Cable  Car. 


46  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


FIG.  27. —  Russian   Government  Engineers  using  Gurley 
Current  Meters  in  Turkestan. 


CURRENT    METERS 


47 


MEASUREMENTS  FROM  BRIDGES 

Occasionally  bridges  may  be  found  well  located  as  re- 
gards stream  gaging.  In  such  cases  it  is  customary  to  mark 
off  measuring  points*  with  paint  on  the  rail  or  string  piece  of 
the  bridge.  The  initial  point  of  the  series  should  be  carefully 
referred  to  a  permanent  object  and  a  careful  description  of 
the  location  written  in  the  note-book. 

A  stayline  is  usually  stretched  above  the  bridge  to  be  used 
when  high  velocities  prevail.  Measurements  from  bridges  are 
made  as  from  cables. 


FIG.  28.—  Typical  Gaging  Station  for  Bridge  Measurement. 


48  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

USE  OF  THE  CURRENT  METER 

The  quantity  of  water  flowing  in  a  stream  is  found  by 
means  of  a  current  meter,  by  subdividing  the  cross-section  of 
the  stream  into  partial  areas  or  panels  and  by  multiplying  each 
partial  area  by  the  mean  velocity  of  the  water  that  flows  past 
each  partial  section,  then  taking  the  sum  of  all  such  products, 

The  cross-section  of  the  stream  is  subdivided  by  verticals 
taken  sufficiently  close  together  to  define  the  area  accurately, 
as  in  cross-sectioning  earthwork;  that  is  to  say,  the  lines  (Fig. 
28)  on  the  stream  bed  between  consecutive  verticals  should 
be  essentially  straight.  On  streams  with  smooth  beds  the  points 
of  observation  will  occur  at  regular  intervals,  but  the  method 
of  computing  the  partial  areas  is  not  dependent  on  the  distance 
apart  of  the  verticals.  The  length  of  each  vertical  in  feet  is 
measured  by  sounding  either  with  a  sounding  rod,  using  an 
engineer's  level  on  the  bank  if  desired,  or  by  a  weight  and  line. 

The  mean  velocity  in  each  partial  area  is  the  average  of 
the  velocities  in  the  verticals  that  bound  the  area.  Velocities 
are  measured  in  feet  per  second;  hence,  the  product  of  the 
partial  area  by  the  mean  velocities  will  be  in  cubic  feet  per 
second.  One  cubic  foot  per  second,  is  the  quantity  of  water 
that  will  flow  past  a  section  of  the  stream  one  foot  wide  and 
one  foot  deep,  with  a  velocity  of  one  foot  per  second. 

SOUNDINGS 

Rods  for  sounding  should  be  of  a  convenient  length  for 
handling  and  may  be  made  either  of  wood  or  of  metal.  Wooden 
rods  should  be  thin  and  sharpened  on  the  edges,  a  section  3 
inches  wide  and  %  inch  thick  being  appropriate  for  a  length 
not  exceeding  five  feet.  Longer  sounding  rods  may  be  made 
from  2x4  inch  lumber,  the  edges  being  worked  so  that  the 
cross  section  of  the  rod  has  the  same  shape  as  the  hull  of  a  ship. 
The  correct  style  of  metal  rod  (Figs.  4,  8  and  9)  is  furnished 
with  all  Gurley  meters. 

Where  there  is  no  danger  of  damaging  the  meter,  the  sound- 
ings are  taken  with  the  meter  on  the  rod  in  all  wading  measure- 
ments. It  should  be  noted  that  the  zero  of  the  graduations  on 
the  rods  is  at  the  center  of  the  cups,  so  that  a  distance  equal  to 
the  distance  from  the  center  of  the  cup,  to  the  bottom  of  the 


CURRENT    METERS 49 

yoke  should  be  added  to  each  reading  on  the  rod  when  sounding. 
In  order  to  prevent  the  sounding  rod  sinking  into  the  bed  of  the 
stream,  it  should  be  provided  with  a  shoe  at  least  3  inches  in 
diameter.  When  using  the ^ rod  care  should  always  be  taken 
that  the  reading  is  not  too  high,  on  account  of  the  impinging 
water  running  up  the^rod.  If  a  sounding  rod  or  line  is  used, 
the  meter  not  being  attached,  the  sounding  are  made  at  all 
measuring  points  before  observing  the  velocities. 

The  soundings  from  bridges  or  cables  are  usually  made 
with  the  weight  and  line,  and  in  such  cases,  with  swift  water, 
a  head  line  is  used  to  hold  the  meter  in  a  vertical  position  to 
prevent  error,  due  to  the  weight  being  carried  down  the  stream 
or  to  the  bowing  of  the  line.  Soundings  with  the  line  are  most 
readily  taken  as  follows:  The  weight  and  line  are  lowered 
until  the  weight  touches  the  bed  of  the  river  directly  under  the 
measuring  point  and,  with  the  line  taut,  a  point  is  marked  on 
it  by  grasping  it  with  the  fingers  opposite  a  fixed  point  on  the 
bridge  or  car;  the  weight  is  then  raised  until  it  just  touches  the 
surface  of  the  water  and  the  length  of  the  sounding  line  that 
passes  the  fixed  point  is  measured.  This  length  is  measured 
by  placing  the  end  of  a  linen  or  metallic  tape  opposite  the 
fixed  starting  point  on  the  sounding  line,  grasping  both  the 
line  and  the  tape  in  the  hands,  and  drawing  up  the  line  and 
tape  without  permitting  them  to  slip  on  each  other  until  the 
weight  reaches  the  surface  of  the  water.  The  length  of  line 
thus  drawn  up,  representing  the  depth  of  the  water,  is  then 
read  directly  from  the  tape.  This  measurement  can  usually 
be  made  by  one  person  with  sufficient  accuracy,  even  when  the 
water  is  from  10  to  12  feet  deep.  On  the  U.  S.  Geological  Sur- 
vey standard  cable  car  a  scale  is  fixed  to  the  frame  of  the  car 
for  measuring  the  depth. 

VELOCITY   OBSERVATIONS 

In  making  a  velocity  measurement,  the  meter  is  held  at 
the  point  in  the  stream  at  which  it  is  desired  to  ascertain  the 
velocity  of  the  current.  The  wheel  is  allowed  to  revolve  for  a 
few  seconds,  in  order  that  it  may  adjust  itself  to  the  current, 
after  which  the  time  for  a  given  number  of  revolutions  is 
noted,  and  the  velocity  is  obtained  from  the  rating  table  for 


50  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

the  meter.  The  run  should  be  from  40  to  70  sec.;  the  number 
of  revolutions  observed,  depending  on  the  velocity  of  the 
water,  should  be  one  of  those  for  which  the  meter  rating  table 
has  been  prepared.  A  check  on  the  work  is  made  by  repeating 
the  observation.  If  the  run  is  not  repeated,  a  check  can  be 
obtained  by  noting  mentally  the  time  for  each  five  revolutions. 
A  stop-watch  is  used  for  observing  the  time,  and  the  record  is 
made  to  the  nearest  %  second.  The  observations  should  be 
recorded  on  properly  prepared  forms.  See  pages  54,  55, 
and  60. 

In  discharge  measurements,  the  mean  horizontal  velocity  in 
a  vertical  at  the  measuring  point  is  desired.  Various  meth- 
ods are  used  for  this  determination,  among  which  the  following 
four  are  most  common:  (a)  Vertical  velocity-curve  method,  (b) 
two-tenth  and  eight- tenth-depth  method,  (c)  six-tenth-depth 
method,  and  (d)  sub-surface  method. 

(a). — By  the  vertical  velocity-curve  method,  measure- 
ments of  horizontal  velocity  are  usually  made  just  beneath  the 
suface,  at  0.5  ft.  below  the  surface,  and  at  each  fifth  to  each 
tenth  of  the  depth  from  the  surface  to  the  bed  of  the  stream, 
and  as  near  the  bottom  as  possible.  These  measured  velocities, 
when  plotted  with  depths  as  ordinates  and  velocities  as  ab- 
scissas, define  for  each  vertical,  the  vertical  velocity-curve  which 
shows  the  velocity  at  every  point  in  the  vertical,  and  from  which 
the  mean  velocity  can  be  determined  by  dividing  the  area 
bounded  by  the  curve,  the  top  and  bottom  ordinates,  and  the 
axis  of  depth  by  the  total  depth.  The  area  may  be  found  by 
planimeter,  or  by  Simpson's  rule  or  Durand's  rule*,  which  will 
be  found  in  books  on  elementary  mechanics. 

Studies  of  vertical  velocity-curves  taken  on  many  streams 
under  various  conditions  of  depth,  velocity,  and  roughness  of 
bed,  show  that  these  vertical  velocity-curves  have  approxi- 
mately the  form  of  a  parabola  in  which  the  axis,  coinciding 
with  the  filament  of  maximum  velocity,  is  parallel  with  the 
surface  and  is  in  general  situated  between  the  surface  and  one- 
third  of  the  depth  of  the  water.  From  the  maximum  the 
velocity  decreases  gradually  upward  to  the  surface  and  down- 
ward nearly  to  the  bottom,  where  it  changes  more  rapidly  on 
account  of  the  friction  on  the  bed.  As  the  depth  and  velocity 
*Hancock,  Applied  Mechanics  for  Engineers. 


CURRENT    METERS 51 

increase,  the  curve  approaches  a  vertical  line  as  its  limiting 
position. 

The  vertical  velocity-curve  method  is  valuable  as  a  basis 
for  the  comparison  of  all  Bother  methods,  for  determining  the 
coefficients  to  be  used  in  reducing  the  values  obtained  by  other 
methods  to  the  true  value,  for  use  under  new  and  unusual  con- 
ditions of  flow,  and  for  measurements  under  ice. 

(b). — In  the  two-tenths-eight-tenths  method,  observations 
of  velocity  are  taken  at  two  points  located  at  depths  of  the 
surface  of  0.2  and  0.8  of  the  depth  in  the  vertical  in  which 
the  measurement  is  made.  The  mean  velocity  is  taken  as  the 
mean  of  the  velocities  at  these  two  points.  This  method  is 
based  on  the  theory*  that  the  vertical  velocity-curve  is  a  parab- 
ola, as  already  stated,  in  which  case  the  mean  of  the  ordinates 
at  0.2114  and  0.7886  depth  below  the  surface  gives  the  mean 
ordinate.  This  is  mathematically  true  for  any  parabola  and 
for  any  position  of  the  thread  of  maximum  velocity.  A  study 
of  a  large  number  of  vertical  velocity-curves  shows  that  this 
holds  true  in  Nature;  and  experience  proves  that  this  method 
gives  more  consistent  results  than  any  of  the  others  except  the 
vertical  velocity-curve  method. 

(c). — In  the  sixth- tenth  method,  the  observation  of  the 
velocity  is  taken  at  a  depth  from  the  surface  equal  to  0.6  of 
the  depth  of  the  stream.  This  method  is  also  based  on  the 
theory**  that  the  vertical  velocity-curve  is  a  parabola  with  the 
maximum  abscissa  between  zero  and  one-third  of  the  depth, 
in  which  case  the  mean  ordinate  is  between  0.58  and  0.67  of 
the  depth  fom  the  surface.  A  study  of  a  large  number  of 
vertical  velocity-curve  measurements  shows  that  the  mean 
depth  of  the  mean  velocity  is  approximately  0.6  of  the  depth. 
This  method  has  the  advantage  of  requiring  a  less  number  of 
velocity  observations,  and  gives  very  satisfactory  results,  but 
not  as  good  as  those  obtained  by  the  two-tenths-eight-tenths 
mefliod. 

(d). — -In  the  sub-surface  method,  the  measurement  of 
velocity  is  made  at  from  0.5  to  1  ft.  below  the  surface,  depend- 
ing on  the  depth  of  the  stream.  The  meter  is  held  at  sufficient 

*  See  "  River  Discharge,"  page  54. 

**  See  F.  W.  Hanna,  M.  Am.  Soc.  O.  E.,  Engineering  News,  January 
11,  1906. 


52  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

depth  to  be  out  of  any  surface  disturbance.  When  this  method 
is  used,  the  velocity  must  be  reduced  by  a  coefficient  to  obtain 
the  mean  velocity.  This  coefficient  varies  from  78  to  987°, 
depending  on  the  depth  and  the  velocity  of  the  stream.  The 
deeper  the  stream  and  the  greater  the  velocity,  the  greater  the 
coefficient.  For  average  streams  in  moderate  freshets,  a  co- 
efficient of  90%  should  be  used;  in  flood  work,  a  coefficient  of 
from  90  to  95% ;  and  for  streams  at  ordinary  stages,  from  85 
to  90%. 

Independent  discharge  measurements,  as  a  rule,  are  of 
but  little  value  in  hydraulic  work  unless  they  are  taken  at 
stages  which  are  known  to  be  either  extremely  low  or  extremely 
high.  In  ordinary  work  it  is  necessary  to  make  a  series  of 
measurements  which,  with  daily  gage  heights  of  the  flow  of 
the  stream,  make  possible  the  computation  of  the  total  flow 
of  the  stream  and  also  its  distribution.  In  connection  with  the 
individual  measurements,  therefore,  it  is  necessary  to  observe 
gage  heights  and  take  full  notes  of  the  conditions  under  which 
the  measurements  are  made,  in  order  to  enable  the  construction 
of  a  station  rating  curve  and  estimate  the  daily  discharge. 

RECORDING  THE  DATA 

The  observations  should  be  noted  at  the  time  they  are 
made  on  properly  prepared  forms  for  discharge  measure- 
ments, shown  on  pages  54,  55  and  60. 

There  should  be  shown  in  these  notes: 
In  column 

1.  The  distance  from  the  initial  point  of  each  vertical 
in  which  soundings  and  velocity  observations  were  made.     The 
distance  between  successive  stations  gives  the  width    of    the 
partial  area.     The  widths  are  written  in  column  11. 

2.  The  depth  of  water  in  the  vertical  at  which  the  obser- 
vation was  made  as  determined  by  the  sounding. 

3.  The  depth  from  the  surface  down  to  that  point  in  the 
vertical  at  which  the  velocity  observation    was    made.     This 
item  is  computed  mentally  in  the  field    before    making    the 
velocity  observation,  and  will  be  two-tenths,  six-tenths,  eight- 
tenths,  etc.,  of  the  depth  recorded  in  column  2,  depending  on 
the  method  used  in  making  the  measurement. 


_____ CURRENT    METERS  53 

4.  The  duration  of  the  velocity  observation  in  seconds 
as  determined  by  means  of  the  stop-watch. 

5.  The  number  of  revolutions  of  the  cups    in   the   time 
noted  in  column  4.     For  convenience  in  computing,  the  num- 
ber of  revolutions  should  bec  one  of  those  appearing  in  the 
rating  table  for  the  rrteter  used. 

Computation  of  the  quantities  to  fill  in  the  remaining  col- 
umns of  the  form  are  made  as  follows: 
Column 

6.  Shows  the  velocity  of  the  water  as  given  by  the  meter 
at  the  point  noted  in  column  3,  and  is  taken  from  that  column 
of  the  rating  table  at  the  head  of  which  appears  the  number 
of  revolutions  shown  in  column  5,  opposite  the  number  of  sec- 
onds noted  in  column  4.    Columns  3,  4,  5  and  6  are  completely 
filled  in  for  each  line  on  which  an  observation  is  noted. 

7.  The  mean  velocity  in  the  vertical  at  any  measuring 
point  is  the  average  of  the  velocity  observations  made  in  that 
vertical.     When  a  single  velocity  observation  is  made  in  any 
vertical  the  value  shown  in  column  7  will  be  the  same  as  that 
shown  in  column  6. 

8.  To  get  the  mean  in  the  section,  or  partial  area,  take 
values  for  consecutive  stations  from  column  7  and  write  their 
average  in  column  8. 

9.  The  number  of  square  feet  in  each  section  or  partial 
area  shown  in  this  column  is  the  product  of  the  mean  depth 
given  in  column  10,  and  the  width  as  given  in  column  11,  ob- 
tained from  notes  in  column  1  as  explained  for  that  column. 

10.  The  mean  depth  of  each  partial  area  is  computed 
by  averaging  the  depth  (column  2)  at  each  vertical  with  the 
depth  (column  2)  at  the  following  vertical. 

11.  The  width  is  the  difference  between    the    distances 
from  the  initial  point  of  consecutive  verticals. 

12.  The  discharge  for  each  section  or  partial    area    is 
the  product  of  factors  given  in  columns  8  and  9. 

Not  more  than  three  significant  figures  should  be  used  in 
the  computations. 

Columns  9  and  12  are  added  and  the  sum  of  the  products 
in  column  12  divided  by  those  in  column  9  to  get  the  mean 
velocity  in  the  entire  cross-section.  The  mean  velocity,  total 
area  and  total  discharge,  are  noted  in  the  appropriate  place  on 
the  form. 


FORM    NO.    H-325. 


DISCHARGE  MEASUREMENT  NOTES. 

Date ,  191 No.  of  Meas ... 

c River  at    }  State  of 

Creek  near 
Width Area Mean  Vel Cor.  M.  G.  H._ _, 

Party Disch. ^ 

Staff  gage,  checked  with  level  and  found 

Chain  length,  checked  with  steel  tape,  12-lb.   pull,  found ft. 

"         "        changed  to ft.  at o'clock.     Correct  length ft. 

"         **        corrected  on  basis  of  levels  to ft.  at o'clock. 

Gage  reading  Time  Station  Meter  No ,. 

Date  rated 

Meas. began ;  ended 

Time  of  meas.    (hrs) Method 

No.  meas.  see's Coef 

Av.  width  sec Av.  depth 

Weighted  mean  G.  Ht ft.  G'  Ht*  chan^e  (totaL>  

Correct          "      "     "      ft.  %  diff.by rating  table, 

Meas.  from  cable,  bridge,  boat,  wading.      Meas.  at ft.  above,   below  gage. 

If  not  at  regular  section  note  location  and  conditions 

Area  from  soundings  (date) 

Method  of  suspension , Stay  wire Approx.  dist.  to  W.  S 

Arrangement  of  weights  and  meter;  top  hole ;  middle  hole ;  bottom   hole 

Gage  inspected,  found Cable  inspected,  found 

Distance  apart  of  measuring  points  verified  with  steel  tape  and  found 

Wind upstr.,  downstr.,  across.     Angle  of  current 

Observer  seen G.  Ht.  book  inspected 

Examine  station  locality  and  report  any  abnormal  conditions  which  might  change  relation  of 
G.  Ht.  to  disch.,  e.  g.,  change  of  control;  ice  or  debris  on  control;  backwater  from;  condition 
of  station  equipment 

Sheet  No.  1  of sheets.     If  insufficient  space,  use  back  of  sheet,  with  reference  letters. 


FIG.  28a. —  Form  No.  H-325,  Discharge  Measurement  General  Data. 


ORM    NO.    H-326. 


DISCHARGE  MEASUREMENT  NOTES 


Date 


19 


No.  of  Meas. 


River,  at 
'Creek,  near" 


Dist.from 
initial 
point 

1 

1 

Depth 

Depth    Time 
of  ob-       in 
servat.  seconds 

r 

Revx 
olux 
tions 

VELOCITY 

Area 

Mean 
Depth 

Width 

Discharge 

At 
point  - 

i. 

Mean 
in 
vertica 

Mean 
in 
section 

• 

i 

V 

Totals 

No of. Sheets.      Comp.by Chk.by Make  notes  on  back. 

FIG.  28b. —  Form  No.  H-326,  Current  Meter  Notes. 


56 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


The  preceding  method  of  calculation  may  be  summed  up 
in  the  following  expression: 


FIG.  29. —  Cross-Section  of  Stream  to  Illustrate  Discharge 
Measurement  Computation. 


In  this  formula,  do,  di,  d2....  dn  and  vo,  vi,  V2....  vn  are  the 
depths  and  velocities  at  the  respective  measuring  sections  ao,  ai, 
a2....an,  which  are  spaced  at  the  distances  h,  L>,  Is  ....In,  which 
is  easily  used  as  explained  above  and  which  gives  accurate 
results.* 

The  field  notes  for  each  measurement,  including  a  prop- 
erly filled  in  copy  of  sheet  1,  should  be  fastened  together  se- 
curely. This  form,  which  is  shown  on  page  54,  should  be 
filled  in  as  soon  as  the  field  notes  have  been  computed.  The 
computations  should  be  made  before  leaving  the  station.  If  the 
measurement  does  not  plot  within  the  limit  of  precision  estab- 
lished for  the  work,  the  computation  should  be  carefully  re- 
viewed and  if  necessary  the  measurement  should  be  repeated. 

It  is  of  great  importance  to  use  the  correct  gage  height 
when  plotting  a  measurement.  The  gage  height  should  be 
read  at  frequent  intervals  during  the  measurement,  and  the 
reading  noted,  together  with  the  time.  The  vertical  at  which 
measurement  is  being  made  at  the  time  of  reading  the  gage 
should  also  be  shown  in  the  notes.  At  a  recording  gage  station 
this  distance  from  the  initial  point  at  which  measurement  is 

*For  a  discussion  of  computation  of  discharge  measurements  by  var- 
ious formulas,  see  article  by  Mr.  J.  C.  Stevens,  M.  Am.  Soc.  C.  E.,  in  Engi- 
neering News,  June  25,  1908. 


CURRENT    METERS 


57 


being  made  at  even  hours  (or  fractions  thereof)  if  the  stage  is 
changing,  is  noted  as  the  measurement  progresses,  and  the 
corresponding  gage  heights  are  later  taken  from  the  automatic 
register.  At  non-recording  -stations,  the  gage  height  is  noted 
similarly  by  reading  either  ,|he  gage  itself,  or  else  distances 
above  or  below  a  more  conveniently  placed  reference  point, 
whose  index  is  in  known  relation  to  the  gage  height. 

To  give  proper  weight  to  the  gage  height  readings,  take  the 
average  of  the  first  and  second  gage  heights  and  multiply  that 
average  by  the  discharge  that  has  been  computed  for  that  part 
of  the  cross-section  between  the  vertical  in  which  observation  was 
made  at  the  time  of  reading  the  first  gage  height,  and  the  verti- 
cal corresponding  to  the  time  reading  of  the  second  gage  height. 
Proceed  similarly  for  the  second  and  third  gage  heights,  third 
and  fourth,  fourth  and  fifth,  and  so  on,  multiplying  each  aver- 
age gage  height  by  the  corresponding  partial  discharge.  Sum 
up  all  the  products  of  average  gage  height  and  partial  dis- 
charge and  divide  this  sum  by  the  total  discharge  as  computed 
by  adding  up  column  12.  The  quotient  is  the  required  weighted 
mean  gage  height. 

LOW  WATER  MEASUREMENTS 

At  many  stations  the  velocity  of  the  river  at  low  stages 
is  so  small  that  it  may  be  advisable  to  find  a  section  nearby 
in  which  the  meter  measurement  may  be  made  by  wading. 


FIG.  30. —  Winter  Measurement. 


CURRENT    METERS 59 

For  such  measurements,  the  meter  on  the  rod  (Fig.  3) 
is  the  most  satisfactory. 

In  order  to  obtain  a  suitable  section,  it  may  be  necessary 
to  cut  off  part  of  the  flow  by  damming  the  stream  and  modifying 
the  channel  so  as  to  get  sufficient  depth  and  velocity  for  meas- 
uring. 

MEASUREMENTS  UNDER  ICE 

When  a  discharge  measurement  is  to  be  made  under  ice,, 
it  is  first  necessary  to  find  a  good  measuring  section.  Such  a 
reconnoissance  can  best  be  made  by  a  hydrographer  who  is 
familiar  with  the  stream  and  who  knows  where  he  will  find 
sections  of  the  stream  with  smooth  beds. 

A  hole  is  first  chopped  through  the  ice  at  the  center  of 
the  stream  at  a  section  being  investigated.  If  this  hole  shows 
that  little  or  no  slush  ice  is  present,  and  the  velocity  is  meas- 
urable, further  investigations  should  be  made  at  each  side.  It 
has  been  found  that  sections  free  of  slush  or  anchor  ice  are 
most  commonly  found  just  above  an  open  place  on  the  river. 

After  the  measuring  section  has  been  selected  a  hole  i& 
chopped  through  the  ice  at  each  measuring  point,  and  the 
depth  and  velocity  determined  with  the  meter  on  the  rod. 
Where  the  depth  and  velocity  are  too  great  the  work  will  have 
to  be  done  with  the  meter  suspended  on  the  meter  cable. 

Ice  measurements  are  usually  made  by  the  .2  and  .8 
method,  and  sometimes  by  vertical  curves.  The  soundings 
should  be  made  to  determine  the  depth  from  the  bottom  of 
the  ice  to  the  bed  of  the  stream  and  the  meter  observations 
taken  at  .2  and  .8  of  this  depth.  In  all  other  respects  ice 
measurements  are  made  and  computed  in  the  same  way  as 
open  water  measurements. 

The  special  jointed  ice  chisel,  ice-measuring  stick  and 
carrying  bag,  generally  used  in  connection  with  ice  measure- 
ments, are  illustrated  in  Fig.  35. 


60 


W.  &  L.  E.  G  U  R  L  E  Y,  TROY,  N.  Y. 


:^^s%^^5^£^ 


OBSERVATIONS                                                        , 

Distance 
from 
initial 
point 

Thickness 
of  ice 

Total  depth 
of  water 

Depth  of 
meter  from 
water  surface 

Time 
in 
seconds 

Revolutions 

Water  surface 
to 
bottom  of  ice 

Effective 
water  depth 

0 

IO 

a 
Z> 

C 

c-Z> 

(c-b)x.2  +  b 
(c-b)*.5+b 
(c-b)x.8*b 

15 

FIG.  34. —  Diagram  indicating  notation  used  in  making  Discharge 
Measurements  under  Ice,  with  Form  for  Notes. 


The   notation   and    a   form   for   recording   the   data   are 
illustrated  in  Fig.  34. 

The   remaining  seven   columns   are   similar   to   those   in 
Form  No.  H-326  (See  page  55). 


CURRENT    METERS 


61 


Solid 


Joint'*! 


Sin.angle 


Ice-measuring  stick 


FIG.  35. —  Ice  Chisel,  Ice  Measuring  Stick,  and  Bag. 


FIG.  3G. — Winter  Measurement. 


62  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

MEASUREMENTS  IN  ARTIFICIAL  CHANNELS 

Current  meter  measurements  of  the  flow  of  water  in 
artificial  channels  must  be  made  with  special  care,  as  the  laws 
of  flow  for  open  channels  are  not  always  applicable  to  arti- 
ficial ones,  because  the  water  level  may  be  subjected  to  dis- 
turbing influences  such  as  undercurrents  caused  by  intakes 
and  outlets  at  rapid  velocities. 

Current  meters  have  been  employed  in  measuring  the  flow 
in  large  conduits.  In  such  cases  apparatus  designed  to  hold 
the  meter  at  a  definite  point  in  the  cross-section  has  been  used. 
The  description  of  such  apparatus  will  be  found  in  the  Transac- 
tions of  the  American  Society  of  Civil  Engineers,  1910,  Vol. 
66. 

Current  meters  have  also  been  used  successfully  for  meas- 
uring the  flow  of  sanitary  sewers.  Details  of  this  work  are  given 
on  page  130. 


ACCURACY  AND  RELIABILITY  OF  THE  CURRENT 

METER 

When  considering  the  accuracy  of  results  obtained  by 
the  current  meter,  account  should  be  taken  of  the  use  to  be 
made  of  the  data.  It  must  be  remembered  that  both  the  total 
flow  of  the  stream  and  its  distribution  over  the  drainage  area 
are  constantly  changing,  and  that  the  conditions  over  the 
drainage  area  are  constantly  changing,  and  that  the  conditions 
existing  at  any  given  time  may  probably  never  occur  again. 
The  flow  which  may  be  expected  in  any  stream,  therefore,  can 
be  determined  only  by  studying  a  series  of  records  extending 
over  a  long  period;  for  this  reason  the  degree  of  refinement 
with  which  the  measurements  are  made  should  be  appropriate 
to  the  use  to  which  they  are  to  be  put. 

As  with  most  instruments,  the  accuracy  and  reliability 
of  the  current  meter  depend  largely  on  the  care  taken  in  the 
measurement  and  the  propriety  of  the  method  used. 


CURRENT    METERS 63 

SELECTION  AND  LOCATION  OF  GAGING  STATIONS 

RECONNOISSANCE 

To  obtain  the  best  results  with  a  current  meter,  stations 
should  be  located  only  at  sjites  well  adapted  to  its  use.  The 
same  careful  attention  should  be  given  to  the  selection  of  a 
current  meter  station  as  is  given  in  establishing  a  system  of 
control  points  for  a  topographic  survey,  in  which  case  the  en- 
tire problem  is  considered  from  all  view  points,  only  such 
control  points  being  located  as  will  give  consistent  and  accur- 
ate results. 

The  final  location  of  the  gaging  station  and  the  choice 
of  equipment  to  be  installed  will  depend  very  largely  on  a 
thorough  reconnoissance.  This  work  is  of  equal,  if  not  greater, 
importance  than  any  other  detail  connected  with  the  location 
of  a  gaging  station.  It  should  be  performed  by  an  engineer 
experienced  in  stream  gaging  work.  Poor  results  obtained  at 
many  stations  may  be  traced  directly  to  the  fact  that  such 
stations  are  not  properly  located. 

When  selecting  and  equipping  a  station,  while  considering 
the  present  use  of  the  data  to  be  obtained  there,  the  importance 
of  all  possible  uses  for  which  the  records  may  be  required  in 
the  future,  under  changed  conditions,  should  be  kept  well  in 
mind,  and  all  the  requirements  should  be  coordinated  as  com- 
pletely as  circumstances  permit. 

If  the  greatest  immediate  value  of  the  data  is  for  a  power 
study  in  a  given  drainage  area,  locate  at  or  near  the  center  of 
the  power  zone  a  primary  or  base  station,  and  elsewhere  as 
many  secondary  stations  as  may  be  necessary.  For  this  par- 
ticular case,  as  in  any  other  water  supply  problem,  the  base 
station  should  be  placed  at  the  strategic  point  on  the  main 
stream,  and  all  data  collected  in  the  basin  should  be  compared 
with  the  data  obtained  at  the  base  station. 

As  the  object  of  the  reconnoissance  is  to  find  the  best  lo- 
cation that  will  furnish  the  desired  data,  it  is  well  before 
locating  the  primary  station  to  examine  the  locality  carefully 
during  various  stages  of  flow,  considering  the  stream  under 
ice  conditions,  as  well  as  during  the  summer  season.  At  low 
stages  the  bed  and  the  minimum  velocity  can  be  examined, 


64  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

and  some  estimate  of  high  water  conditions  can  also  be  made, 
while  at  medium  and  high  stages  it  is  usually  impossible  to 
examine  the  bed  or  estimate  low  stage  velocities.  A  stream 
in  a  lumbering  section  must  be  watched  closely  during  the 
log-driving  period.  Locations  at  which  log  jams  usually  form 
should  be  avoided. 

When  the  problem  of  locating  stations  involves  an  entire 
drainage  basin,  an  hydraulic  engineer  familiar  with  the  basin 
will  likely  have  in  mind  tentative  locations  for  the  primary 
station  and  for  supplementary  stations,  and  will  extend  his 
reconnoissance  by  making  examinations  at  different  river 
stages  at  numerous  points  in  the  basin  as  he  may  have  occasion 
to  go  back  and  forth  in  it.  For  locating  secondary  stations 
careful  reconnoissances  are  also  required,  but  they  are  usually 
made  more  rapidly. 

If  the  project  for  which  the  data  are  collected  depends 
on  continuous  flow,  and  there  are  few  or  no  storage  possibili- 
ties, the  essential  data  will  be  that  giving  the  amount  of  the 
minimum  flow,  and  the  period  for  which  it  continues.  If  op- 
portunities for  storage  do  exist,  then  the  maximum  flow  will 
be  of  equal  importance.  Satisfactory  results  are  usually  ob- 
tained if  these  two  extreme  conditions  are  allowed  to  deter- 
mine the  location  of  the  station. 

The  following  essentials  should  be  carefully  examined: 

1.  The  general  course    of    the    stream    above,    at    and 
below,  the  station,  noting  whether  the  course  of  the  stream  is 
straight  or  whether  curved. 

2.  The  average  depth  and  velocity  of  the  stream  at  the 
section  under  consideration. 

3.  The  character  and  location  of  the  control  point,  with 
reference  to  the  proposed  location  of  the  gage. 

4.  The  character  of  the  stream  bed,  whether  of  sand, 
gravel,  boulders  or  rock,  and  especially  whether  it  is  shifting 
or  permanent. 

5.  The  character  of  the  stream  banks  at  the  proposed 
section,  whether  high  or  low,  clear  or  wooded,  permanent  or 
changing. 

6.  The  relative  position  of    dams    and    the    mouth    of 
tributary  streams  relative  to  the  proposed  location,  consider- 


C  U  R  R  E  N  T    METERS 65 

ing  carefully  the  effect  of  these  on  the  gage  heights  and  the 
measurements. 

7.  The  availability  of  observers  or  attendants,  and  their 
qualifications  for  the  work.    .* 

8.  The  most  appropriate  type  of  gage,  whether  record- 
ing or  non-recording.^ 

If  no  records  are  available  concerning  the  diurnal  fluctu- 
ations, such  records  should  be  secured  at  once  by  installing  a 
portable  automatic  register  (See  Register  No.  633,  Fig.  50). 
The  results  of  this  test  will  show  whether  an  automatic  gage 
installation  is  necessary. 

9.  For  an  automatic  water  stage  register,  a  survey  of  the 
location  decided  upon,  to  fix  the  character  of  the  soil  in  which 
the  well  must  be  dug,  the  depth  of  the  well,  and  the  length  of 
the  intake  pipe;  for  a  vertical  staff  gage,  the  character  of  sup- 
port available  and  the  length  of  gage  rod  required;  for  an 
inclined  staff  gage,  the  character  of  the  banks,  the  nature  of 
the  support  for  the  gage,  and  its  length;  for  a  chain  gage,  the 
character  of  support  available  and  the  length  of  chain  required. 

10.  The  available  or  required  structures  from  which  to 
make  measurements. 

If  a  bridge,  a  general  sketch  of  the  vicinity  showing  es- 
pecially high  water  lines,  and  a  sketch  of  the  bridge  itself, 
showing  the  material  of  which  it  is  built,  the  length  and  num- 
ber of  spans,  and  its  height  above  water. 

If  a  cable,  the  length  of  span,  the  kind  and  height  of  sup- 
ports available  or  required,  and  the  foundation  available  for 
them. 

Some  practical  details*  will  be  of  assistance.  The  prin- 
cipal sources  of  error  in  gaging  streams  by  current  meters  are 
due  to  the  effect  on  the  water  stage  of  slack  or  nearly  slack 
water  in  any  part  of  the  cross-section,  to  backwater  from  dams 
or  other  obstructions,  or  from  tributaries,  which  may  cause 
the  river  stage  to  rise  without  a  proportional  increase  in  dis- 
charge, and  from  obstructing  ice.  Do  not  choose  a  site  im- 
mediately above  or  below  the  junction  of  two  important 
branches.  Fig.  37  shows  a  gaging  station  where  the  reconnois- 

*These  suggestions  have  been  taken  from  a  paper  by  C.  C.  Covert,  M. 
Am.  Soc.  C.  E.,  District  Engineer,  U.   S.  Geological  Survey. 


66 


W".  &  L.  E.  GURLEY,  TROY,  N.  Y. 


sance  was  hurriedly  made,  and  where  the  gages  were  put  in 
without  any  consideration  to  the  effect  of  their  location  on  the 
resulting  records.  The  example  given  is  that  of  two  gaging 
stations  on  an  eastern  river,  one  on  the  east  branch  and  the 
other  on  the  west  branch.  From  the  gages  to  the  junction  of 
the  two  branches  is  approximately  one  and  a  half  miles.  The 
difference  of  elevation  of  the  water  surface  at  the  two  points 
is  less  than  two  feet  at  all  normal  stages.  During  high  water 
periods  there  is  always  back  water  at  one  or  both  of  the  gages. 
While  it  is  possible  to  determine  the  amount  of  back  water, 
it  would  be  expensive,  and  would  have  to  be  repeated  at  each 
successive  flood,  because  the  different  conditions  of  flow  pro- 
duce different  conditions  of  back  water.  On  the  west  branch 
of  the  stream  a  chain  gage  was  located  near  the  center  of  a 


About  /fz 
June  f/ on  nf/ttt£<. 

L  acaf/ori 


FIG.  37. —  Showing  poor  location  of  Gaging  Station,  because 

of  junction   of   two    branches    causing   backwater.      The 

location  of  gages  at  each  station  is  also  poor. 


CURRENT    METERS 


67 


suspension  bridge.  This  is  an  extremely  bad  arrangement. 
There  may  be  considerable  stretch  to  the  chain,  but  the  uncer- 
tainty as  to  the  amount  of  rise  and  fall  due  to  expansion  and 
contraction  of  the  suspension  bridge  is  even  more  than  the 
stretch  of  the  chain.  At  this.<  station  there  was  an  opportunity 
to  anchor  the  chain  ^age  to  one  of  the  towers  and  to  install  a 
staff  gage  on  the  rocks,  the  shore  on  the  left  side  beneath  the 
bridge  being  rocky  and  almost  vertical. 

At  the  station  on  the  east  branch  the  chain  gage  is  used 
suspended  from  the  upstream  side  of  the  highway  bridge.  A 
short  distance  below  the  highway  bridge  is  a  railroad  bridge. 
This  railroad  bridge  invariably  causes  back  water  at  the  high- 
way bridge  during  the  breakup  of  the  ice.  Had  the  gage  at 


extresne 


FIG.  38.  —  Showing  proper  and  improper  location  of 
Gaging  Stations. 


68 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


this  station  been  a  staff  gage  and  fastened  to  the  downstream 
side  of  the  railroad  bridge,  the  records  would  never  have  been 
affected  by  the  back  water  from  either  bridge,  since  the  con- 
troling  point  for  stream  flow  under  natural  conditions  is 
300  ft.  or  400  ft.  below  the  railroad  bridge.  The  records  would 
then  have  given  much  better  results  during  the  high  stages. 


O/d  dam  j3art/a//y 
desiroyed 


Large  bov/cters  and 
wry  rot/gti  c/?ar?/?e/  cause 

t°9   ar?d  JCC  JGS77S. 

Log  jams  issue  fly  fast 
to* 


FIG.  39. —  Showing  poor  location  of  Gaging  Station  due  to  channel 
conditions  which  cause  periodic  log  and  ice  jams. 


CURRENT    METERS     69 

At  another  station  a  sloping  staff  gage  was  installed, 
about  twelve  feet  upstream  from  the  bridge  abutment,  Fig.  38. 
A  vertical  staff  gage  for  high  water  period  was  installed  on 
the  upstream  corner  of  one  of  the  abutments.  Thus,  both  of 
these  gages  are  located  so4hat  if,  for  any  reason,  there  are 
back  water  conditions  at  this  bridge  due  to  ice  or  logs  jamming 
on  the  piers,  the  gage  heights  will  be  correspondingly  affected. 
The  proper  procedure  for  installing  these  gages  would  have 
been  to  place  the  vertical  staff  gage  on  the  downstream  side 
of  the  abutment  and  to  place  the  sloping  staff  gage  for  low 
water  measurements  in  a  line  with  the  first  gage.  Had  this 
been  done,  ice  jams  or  any  other  back  water  conditions  on  the 
upstream  side  of  the  bridge  would  not  affect  the  gage  readings, 
while  at  the  same  time  the  vertical  staff  gage  would  have  been 
protected  from  the  ice  and  debris  which  floats  in  the  stream 
during  high  water. 

Fig.  39  illustrates  another  difficulty.  In  this  case  the 
gage  was  placed  on  the  bridge  because  it  was  convenient,  and 
also  because  the  persons  desiring  the  records  were  in  a  hurry 
for  data  and  did  not  care  to  spend  time  and  money  on  proper 
reconnoissance.  The  station  was  maintained  four  years. 
During  the  winter  months  it  was  always  difficult  to  obtain 
measurements  on  account  of  ice  conditions,  and  during  the 
spring  there  were  always  log  jams.  The  channel  conditions 
were  very  rough  and  a  portion  of  the  log  jams  always  remained 
during  the  summer  months.  In  order  to  follow  continually 
changing  conditions  it  was  necessary  to  make  a  large  number 
of  measurements  at  a  correspondingly  high  cost  for  mainten- 
ance. Even  with  this  done,  the  results  obtained  were  only 
approximate.  As  many  as  four  temporary  curves  were  drawn 
and  the  exact  period  of  each  rating  was  uncertain.  The  oper- 
ating cost  for  four  years  at  this  station  was  more  than  the 
entire  cost  of  installation  at  the  station  eventually  located  two 
miles  further  downstream,  at  which  accurate  results  were  ob- 
tained at  a  low  operating  cost.  At  the  last  station  there  are 
some  difficulties  from  ice  conditions  during  Winter  months, 
but  it  is  possible  with  frequent  measurements  to  overcome 
this  in  a  satisfactory  manner.  In  view  of  the  lack  of  time  at  the 
start  to  give  the  river  a  thorough  reconnoissance,  it  would 


70  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

have  been  cheaper  ultimately  to  have  used  a  cable  to  overcome 
the  poor  channel  conditions  at  the  bridge. 

In  selecting  a  gaging  station  the  judgment  should  not  be 
unduly  influenced  by  existing  bridges  or  other  convenient 
structures  for  supporting  the  gage,  or  from  which  measure- 
ments may  be  made.  Better  results  will  be  obtained  at  smaller 
cost  if  these  structures  are  ignored  and  the  attention  confined 
to  the  hydraulic  features.  The  same  mature  consideration 
should  be  given  the  cost  of  operating  the  station  as  to  the  first 
cost  of  its  installation. 

OBSERVERS 

The  presence  of  a  reliable  observer  is  often  a  controlling 
factor  in  establishing  a  station.  In  many  places  this  fact  can- 
not be  ignored,  but  where  there  is  a  choice  the  station  should 
be  placed  at  the  most  favorable  location,  and  should  not  be 
subordinated  to  the  convenience  of  the  observer.  The  intro- 
duction of  automatic  registers  which  meet  successfully  all  of  the 
requirements  at  isolated  places  have  solved  many  of  the  per- 
plexing problems  arising  from  the  absence  of  observers  at  such 
stations. 

ESTABLISHMENT   OF   STATIONS 

After  the  reconnoissance  has  fixed  the  location  and  type 
of  the  station,  its  equipment  is  then  installed.  The  most  ap- 
proved practice  in  the  equipment  of  current  meter  gaging 
stations  will  be  found  in  (U.  S.  Geological  Survey)  Water 
Supply  Paper  No.  371*,  which  may  be  obtained  from  the  Direc- 
tor, U.  S.  Geological  Survey,  Washington,  D.  C.,  while  the  most 
approved  methods  of  observing  and  preparing  the  data  will  be 
found  in  "River  Discharge."  ** 

Briefly,  such  stations  for  determining  the  total  flow  of  a 
stream  and  its  diurnal  fluctuations  need  in  general  the  fol- 
lowing equipment: 

1.  A  gage  or  gages  to  indicate  or  to  record  the  fluctua- 
tions of  stage. 

*Equipment  for  Current  Meter  Gaging  Stations,  by  Geo.  J.  Lyon,  M. 
Am.  Soc.  C.  E. 

**For  sale  by  W.  &  L.  E.  Gurley,  $2  net.,  postpaid. 


CURRENT    METERS 71 

2.  Bench  marks  to  refer  the  gages  to  a  fixed  datum,  and 
to  indicate  whether  the  gages  remain  at  the  correct  elevation. 

3.  Structures  to  protect  the  automatic  water  stage  regis- 
ter when  used. 

4.  Structures*  from  which  discharge  measurements   are 
made. 

5.  Stay  line  and  head  line  to  hold  the  meter  in  a  vertical 
position  when  soundings  and  velocity  observations  are  made. 

6.  Graduated  lines  to  indicate  the  points  of  observation. 

7.  Structures  to  control  and  regulate    the    relation    be- 
tween stage  and  discharge  at  places  where  natural  control  is 
lacking. 

Items  3  to  6  are  illustrated  in  Fig.  25,  which  shows  a 
typical  gaging  station,  while  item  7  is  illustrated  in  Fig.  21. 
Full  details  are  given  in  (U.  S.  Geological  Survey)  Water 
Supply  Paper  No.  371. 


GAGES 

The  entire  process  of  collecting  stream  flow  data  by  cur- 
rent meter  methods,  is  based  on  the  constancy  of  the  relation 
between  gage  height  and  discharge.  Hence,  the  correct  in- 
stallation of  the  gage  and  its  correct  reading  are  fundamentally 
important.  Errors  in  reading  or  recording  the  gage  height  are 
known  to  be  the  reason  for  the  majority  of  inaccuracies  in 
stream  gaging  work. 

The  instruments  that  have  been  used  for  indicating  the 
elevation  of  water  surface  of  rivers,  lakes,  and  other  bodies  of 
water  may  be  grouped  into  two  general  classes,  comprising  re- 
spectively non-recording  gages  and  recording  water  stage  regis- 
ters, the  grouping  depending  on  the  method  of  obtaining  the 
record,  whether  by  direct  readings  by  an  observer  at  stated  in- 
tervals from  a  scale  board,  or  other  device,  or  by  some  auto- 
matic mechanism. 

NON-RECORDING  GAGES 

Non-recording  gages  in  common  use  are  the  vertical  or 
inclined  staff  gage,  the  hook  gage,  the  chain  gage,  and  the  float 


72 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


The  staff  gage,  whether  vertical  or  inclined,  is  the  most 
satisfactory  non-recording  gage  for  all  ordinary  conditions. 
In  many  cases  it  is  possible  to  read  staff  gages  more  accurately 
if  a  stilling  box  is  used.  A  small  box  without  a  cover,  and  with 


FIG.  40. — Vertical  and  Inclined  Staff  Gages. 

one  end  removed,  just  wide  enough  to  slide  along  the  bedpiece, 
makes  an  excellent,  simple  device  for  this  purpose.  The  box 
turned  upside  down,  is  placed  on  the  gage  each  time  it  is  read, 
being  stored  above  high  water  when  not  in  use. 

In  some  situations,  two  gages  (Fig.  40)  are  desirable,  one 
for  low  and  the  other  for  high  water. 

Hook  gages  are  used  in  stream  gaging  work  in  the  wells 
where  automatic  registers  are  installed,  or  elsewhere  for  special 
investigations. 


CURRENT    METERS 


73 


GURLEY  HOOK  GAGE 

This  new  type  of  Hook  Gage  is  a  great 
improvement  over  other  patterns.  Its  entire 
arrangement  is  such  that  the  readings  can 
be  taken  by  the  observer  with  the  greatest 
possible  convenience  and  at  some  distance 
from  the  surface  of  the  stream  or  ditch 
being  measured.  This  is  often  a  decided 
advantage,  especially  so  in  the  East,  where 
many  of  the  streams  are  contaminated  by 
dye  stuffs  and  other  undesirable  material, 
rendering  it  unpleasant  for  the  observer  to 
get  too  close  to  the  water. 

The  Hook  Gage  is  made  entirely  of 
metal  and  is  nickel  plated  throughout.  The 
tube  is  regularly  made  to  read  to  2.2  feet 
but  may  be  made  longer  if  desired.  It  is 
graduated  to  feet,  tenths  and  hundredths, 
and  is  read  to  thousandths  by  a  vernier, 
which  is  capable  of  fine  adjustment  by 
means  of  a  slow  motion  screw.  Elongated 
holes  in  the  base  furnish  means  for  bolting 
the  gage  to  the  side  of  the  flume.  The 
hook  is  adjustable  within  the  tube  and 
allows  for  a  movement  of  12  inches  inde- 
pendent of  the  gage,  thus  permitting  it  to  be 
set  accurately  to  the  exact  surface  of  the 
water. 


FIG.  41.—  No.  628 
Hook  Gage. 


TO  USE  THE  GURLEY  HOOK  GAGE 

The  hook  gage  is  used  in  a  box  attached  to  a  flume  at  any 
convenient  point  near  the  weir,  the  water  from  the  flume  being 
conveyed  to  the  box  by  rubber  or  lead  pipes,  thus  indicating 
the  precise  level  of  the  water  in  the  flume,  the  surface  of  the 
water  in  the  box  being  at  rest. 

When  the  depth  of  the  water  passing  over  a  weir  is  re- 
quired, the  exact  level  of  the  crest  of  the  weir  should  be  taken 
by  a  leveling  instrument  and  rod,  and  marked  by  a  line  drawn 


74          W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

in  the  still  water  box  at  the  surface  of  the  water.  The  scale 
of  the  gage  being  previously  set  at  zero  with  the  vernier,  the 
base  is  fastened  to  the  box  above  the  water  in  a  vertical  position 
and  at  such  a  height  that  the  point  of  the  hook  is  at  the  same 
level  as  the  crest  of  the  weir,  the  precise  point  being  secured 
by  moving  the  hook  in  the  tube.  The  point  of  the  hook  will 
of  course  be  under  water  and  level  with  the  crest  of  the  weir. 

The  depth  of  water  flowing  over  the  weir  is  the  distance 
between  the  point  of  the  hook  in  the  position  named  and  the 
exact  surface  of  the  water.  To  ascertain  this,  the  hook  is 
raised  by  turning  the  milled  head  nut  until  the  point  of  the 
hook,  appearing  a  little  above  the  surface,  causes  a  distortion 
in  the  reflection  of  the  light  from  the  surface  of  the  water.  A 
slight  movement  of  the  hook  in  the  opposite  direction  will  cause 
the  distortion  to  disappear,  and  will  indicate  the  surface  with 
precision.  The  reading  of  the  scale  will  then  give  the  depth 
of  water  passing  over  the  weir,  in  thousandths  of  a  foot. 

It  will  be  understood  from  the  illustration  that  the  longer 
movements  of  the  scale  are  made  by  loosening  the  large  clamp 
screw  and  sliding  the  graduated  tube  through  the  frame,  the 
finer  adjustments  being  made  by  the  milled  nut. 


Floating  gages  to  record  only  maximum  and  minimum 
stages  are  used  occasionally  where  such  information  is  sufficient. 

Chain  gages  may  sometimes  be  used  in  situations  where 
no  other  type  could  be  installed.  Great  care  should  be  taken 
to  secure  a  rigid  support  for  a  chain  gage. 

All  gages  should  be  placed  so  that  they  may  be  easily 
read.  The  scales  of  non-recording  gages  should  be  divided 
into  feet  and  tenths.  When  it  is  desirable  for  the  ordinary 
gage  reader  to  read  closer  than  tenths  of  a  foot,  the  tenths  should 
be  divided  into  halves  and  quarters  rather  than  into  hundredths. 
Experience  has  shown  that  the  ordinary  observer  is  able  to 
read  common  fractions  of  a  tenth  more  readily  than  decimal 
fractions.  Where  skilled  observers  are  available  the  decimal 
system  may  be  used. 


CURRENT    METERS 75 

To  insure  accurate  marking,  all  gages  should  be  subdi- 
vided, either  by  means  of  a  steel  tape  or  an  engineer's  level. 
The  zero  of  all  gages  should  be  accurately  referred  to  a  fixed 
datum,  and  the  relation  thus  established  should  be  checked  fre- 
quently by  means  of  an  engineer's  level. 

RECORDING  WATER  STAGE  REGISTERS 

Recording  water  stage  registers  make  a  record  of  stage, 
either  continuously  by  a  curve,  the  coordinates  of  which  indi- 
cate the  time  and  the  stage,  or  by  a  device  that  prints  at  stated 
intervals  of  time.  The  essential  parts  of  the  recording  gage 
are:  (1)  A  float  which  rises  and  falls  with  the  surface  of  the 
water;  (2)  A  device  for  transferring  the  vertical  motion  of  the 
float  to  the  record,  either  directly  or  through  a  reducing  mechan- 
ism; (3)  The  recording  device;  and  (4)  The  clock. 

Gurley  recording  water  stage  registers  are  described  in 
detail  on  pages  77  to  117. 


BENCH  MARKS 

The  value  of  all  streamflow  records  depends  so  intimately 
upon  the  constant  relation  between  zero  of  the  gage  and  the 
station  bench  mark  that  too  much  care  cannot  be  taken  to  in- 
sure the  permanence  of  this  relation. 

Two  independent  bench  marks  at  each  station  are  desir- 
able. They  should  be  so  located  that  they  will  not  be  damaged 
by  floods  or  other  causes.  At  bridge  stations  at  least  one  bench 
mark  should  be  apart  from  the  structure.  Where  trees  are 
available,  a  track  spike  with  the  front  edge  of  the  head  up- 
turned, makes  a  useful  bench  mark.  In  a  locality  without  tim- 
ber the  United  States  Geological  Survey  type  bench  mark 
(Fig.  42)  is  available.  To  set  it,  dig  a  hole  of  small  diame- 
ter with  a  post  hole  digger,  well  below  frost  line.  Place  in  the 


76 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


FIG.  42. —  United  States  Geological  Survey  Bench  Mark. 

hole  a  piece  of  3-inch  pipe  and  fill  the  hole  with  concrete;  fill 
the  pipe  with  cement  mortar,  into  which  set  the  bench  mark 
tablet.  Always  place  the  tablet  with  the  axis  of  the  stem  verti- 
cal, so  that  the  circle  marking  the  elevation  is  actually  the 
highest  point  of  the  bench  mark. 

Avoid  placing  bench  marks  on  new  or  unstable  structures. 
Wherever  possible,  place  the  bench  mark  so  that  the  gage  may 
be  reached  in  one  set  up. 

Having  established  the  station  bench  mark,  its  location 
with  respect  to  prominent  objects  should  be  carefully  described. 
While  in  some  cases  it  may  be  desirable  to  know  the  elevation 
of  the  gage  datum  above  sea  level,  much  confusion  will  be 
avoided  if  an  arbitrary  elevation,  applicable  to  all  emergencies 
and  future  conditions,  is  assigned,  and  only  that  elevation  used 
in  station  descriptions. 


PART  II. 

GURLEY  AUTOMATIC  WATER  STAGE  REGISTERS 

THEIR  CONSTRUCTION,  INSTALLATION 

AND  OPERATION 

INTRODUCTION 

For  the  purpose  of  obtaining  continuous  records  of  stream 
flow,  it  is  necessary  to  establish  and  to  equip  permanent  stream 
gaging  stations  and  to  observe  and  tabulate  certain  data. 

For  each  gaging  station,  a  station  discharge  table  showing 
the  discharge  corresponding  to  all  gage  heights  within  the 
range  of  stage  is  prepared.  The  relationship  between  gage 
height  and  discharge  remains  constant  as  long  as  the  control  is 
unchanged,  so  that  as  long  as  the  gage  heights  are  accurately 
read  and  carefully  recorded  the  data  obtained  will  be  accurate. 

The  discharge  of  uniformly  flowing  unregulated  streams 
at  well  selected  gaging  stations  may  be  obtained  by  applying 
to  the  station  discharge  table  two  daily  gage  heights  per  day, 
of  which  one  is  usually  taken  in  the  morning  and  the  other  in 
the  evening.  But  such  gage  heights  read  morning  and  evening 
will  not  take  account  of  sudden  increases  in  stage  due  to  floods, 
or  to  those  due  to  regulation  of  the  flow.  To  take  account  of 
such  variations,  including  those  incident  to  power  regulations 
of  the  stream,  which  materially  affect  the  estimates  of  run-off 
(sometimes  affecting  the  monthly  means  as  much  as  30  per 
cent.),  it  is  necessary  to  install  automatic  water  stage  registers. 
It  is  also  highly  desirable,  and  in  many  cases,  as  a  matter  of 
record,  is  essential,  to  use  them  at  any  station  from  which  the 
records  are  to  be  used  as  a  basis  of  proportioning  the  stream 
flow  among  a  number  of  users,  as  in  power,  irrigation,  and 
mining  practice. 

CONDITIONS  REQUIRING  THE  USE  OF  AUTOMATIC 
WATER  STAGE  REGISTERS 

The  conditions  requiring  the  use  of  automatic  registers 
have  been  admirably  discussed  in  detail  by  the  Engineers  of 
the  United  States  Geological  Survey.** 

**By  Mr.  Glenn  A.  Gray,  M.  Am.  Soc.  C.  E.,  District  Engineer,  in  a 
paper  before  a  Conference  of  Engineers  of  the  Water  Resources  Branch, 
U.  S.  Geological  Survey,  Washington,  D.  C.,  December,  1914. 

By  Mr.  C.  H.  Pierce,  M.  Am.  Soc.  C.  E.,  District  Engineer,  in  Contribu- 
tions to  Hydrology,  1915,  Water  Supply  Paper  375-F,  U.  S.  Geological  Survey. 


78  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

It  may  be  said  that  automatic  water  stage  registers  are 
necessary : 

1.  WHERE  WATER  is  VALUABLE  AND  EXCEPTIONALLY 

ACCURATE  RECORDS  ARE  NECESSARY. 

In  irrigation  enterprises  information  concerning  the 
quantity  of  water  that  can  be  supplied  is  necessary  to  interest 
capital,  and  the  accuracy  of  the  stream-flow  records  will  deter- 
mine not  only  the  feasibility  of  a  project,  but  in  a  large  meas- 
ure the  future  of  the  community  interested.  Recent  develop- 
ment in  the  West  has  created  a  demand  for  water,  and  the 
quantity  available  must  be  accurately  measured  before  the 
water  subject  to  filing  or  the  quantity  in  excess  of  prior  rights 
is  known.  Owing  to  lack  of  stream-flow  data,  many  streams  are 
over  appropriated  by  water  users.  Often  the  discharge  of 
the  streams  on  which  such  conditions  exist  is  small  and  difficult 
to  measure.  In  determining  the  flow  of  a  stream  subject  to  ad- 
ditional appropriation  of  water,  the  automatic  register  is  abso- 
lutely necessary. 

2.  WHERE  THE  ARTIFICIAL  OR  NATURAL  CONDITIONS  ON  A 
STREAM  CAUSE  SUDDEN  CHANGES  IN  STAGE  DURING  THE  24-HOUR 

PERIOD. 

Sudden  changes  in  stage  due  to  natural  conditions  may 
occur,  on  streams  draining  areas  of  high  altitude  and  fluctuat- 
ing with  melting  and  freezing  snows.  A  stream  subject  to 
change  because  of  the  climatic  conditions  may  show  great  var- 
iation in  stage  within  the  24-hour  period,  especially  during  the 
spring  or  when  the  mountain  snows  are  melting,  the  effect  de- 
pending to  a  certain  extent  on  the  distance  between  the  gaging 
station  and  the  mountainous  section  of  the  drainage  area.  At 
a  station  in  the  mountains  and  near  the  source  the  stage  gener- 
ally increases  during  the  day  and  decreases  at  night;  at  a 
station  farther  from  the  source  or  mountainous  section  the  time 
of  increase  or  decrease  in  stage  varies  according  to  the  dis- 
tance. Reservoirs  storing  stream  water  for  use  as  occasion  de- 
mands, either  for  power  or  for  irrigation,  or  both,  produce 
artificial  conditions  that  may  cause  sudden  changes  in  stage. 
To  obtain  an  accurate  record  of  changes  in  stage  irregular  in 
intervals  and  unequal  in  magnitude,  and  also  of  the  quantity 
of  water  released  from  storage  reservoirs  as  well  as  of  the  flow 
not  stored,  an  automatic  register  is  essential. 


WATER    STAGE     REGISTERS  79 

3.  WHERE  RECORDS  ARE  DESIRED   ON  A  FLOOD-WATER 
STREAM  WHICH  IS  DRY  MOST  OF  THE  YEAR. 

Records  of  flow  of  a  flood-water  stream  whose  channel  is 
dry  most  of  the  year  are  very  difficult  to  obtain.  Streams  of 
this  type  carry  water  at  times  of  melting  snow  or  of  heavy  rain- 
fall. The  rain  may*  come  in  the  form  of  a  cloud-burst  and  the 
floods  resulting  are  of  short  duration,  perhaps  15  or  20  min- 
utes. Even  if  a  staff  gage  and  a  gage  reader  were  available, 
the  flood  would  pass  the  gage  before  the  reader  arrived  there. 
The  duration  of  the  flood  depends  largely  on  the  size  and  char- 
acter of  the  drainage  area  and  the  distribution  of  the  rain  fall. 
An  automatic  register  is  necessary  if  a  true  hydrograph  of 
the  stream  is  to  be  obtained.  The  float  of  such  a  register 
is  usually  carried  up  with  great  force  and  rapidity  when  the 
wall  of  water  or  bore  of  the  flood,  sometimes  15  or  20  feet 
high,  reaches  the  register.  Much  foresight  must  be  used  to 
prevent  damage  to  the  automatic  register  from  such  sources. 

4.  WHERE  COMPLETE  RECORDS  ARE  DESIRED  ON  A  STREAM 

WHICH  FLOWS  CONTINUOUSLYBUT  IS  SUBJECT  TO  SUDDEN  FLOODS. 

The  flow  of  a  perennial  stream  that  is  not  subject  to  floods 
can  be  accurately  determined  by  readings  from  a  staff  or  chain 
gage;  but  a  stream  subject  to  sudden  floods  can  not  be  accur- 
ately gaged  without  automatic  instruments.  Not  uncommonly 
the  gage  reader  at  a  station  where  a  staff  or  chain  gage  is  used 
makes  two  readings  daily — morning  and  evening.  If  a  heavy 
rain  occurs  between  the  time  of  these  two  readings  and  causes 
a  sudden  flood  it  is  more  than  probable  that  the  morning  and 
afternoon  gage  heights  will  give  no  indication  of  the  change 
in  stage,  but  will  simply  show  a  constant  discharge.  Since  a 
large  proportion  of  the  total  run-off  from  a  basin  occurs  at 
times  of  flood,  a  true  index  of  the  flood-flow  must  be  obtained. 
Conditions  stated  under  3  and  4  are  similar,  in  that  flood  waters 
furnish  a  large  proportion  of  the  total  run-off. 

5.  WHERE  IT  is  NECESSARY  TO  DETERMINE  THE  MAXIMUM 

GAGE  HEIGHT  OR  THE  MAXIMUM  DAILY  MEAN  GAGE  HEIGHT. 

The  necessity  for  a  record  showing  maximum  gage  heights 
or  the  maximum  daily  mean  gage  height  arises  principally  in 
connection  with  the  design  of  power  dams  and  bridges.  If  a 
stream  is  subject  to  frequent  floods  during  the  year  and  the 
maximum  gage  height  must  be  determined,  a  continuous  hydro- 


80  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

graph  for  365  days  is  necessary.  The  peak  of  a  flood  can  be 
ascertained  by  observation  of  the  driftwood  at  the  gaging 
station  but  a  record  of  its  duration  would  not  be  available  un- 
less constant  attention  was  given  by  the  gage  reader.  If  the 
maximum  daily  mean  gage  height  is  desired,  the  hydrograph 
from  an  automatic  register  is  even  more  essential.  The  mean  ob- 
tained from  a  staff  or  chain  gage  read  twice  daily  might  indi- 
cate a  different  day  of  maximum  from  that  shown  by  automatic 
recording  register.  The  day  of  maximum  gage  height  is  not 
always  the  day  of  maximum  daily  mean  gage  height.  Two 
daily  readings  might  indicate  several  days  during  a  year  as 
days  of  maximum  mean  gage  height,  within  a  small  per  cent 
of  each  other,  whereas  an  automatic  register  record  would 
doubtless  show  entirely  different  results.  The  accuracy  re- 
quired for  such  data  would,  of  course,  play  an  important  part 
in  the  selection  of  the  type  of  gage,  but  for  a  record  which 
would  be  beyond  question  an  automatic  register  is  necessary. 

6.  WHERE  IT  is  NECESSARY  TO  DETERMINE  THE  MINIMUM 

GAGE  HEIGHT  OR  THE  MINIMUM  DAILY  MEAN  GAGE  HEIGHT. 

The  necessity  for  a  record  of  the  minimum  gage  height 
or  minimum  daily  mean  gage  height  occurs  in  connection  with 
water  power  and  irrigation  practice.  The  minimum  flow  of  a 
stream  in  amount  and  duration  is  one  of  the  controlling  factors 
of  a  water  power  project,  and  the  duration  of  the  period  of 
flow  should  always  be  determined  with  accuracy.  In  some 
places  flood  water  may  be  stored  to  replenish  the  low  flow;  a 
continuous  record  should,  therefore,  be  obtained  to  determine 
the  amount  of  storage  required.  In  irrigation  projects  the  low- 
water  flow  is  not  so  essential  unless  the  low-water  period  occurs 
in  the  irrigation  season  and  the  quantity  of  water  required  is 
in  excess  of  the  supply. 

7.  WHERE  SMALL  STREAMS  OF  SUDDEN  FLUCTUATION  ARE 
MEASURED  BY  WEIRS  FOR  ADJUDICATION   OF  WATER  BY  THE 

COURTS. 

The  mean  of  three  or  four  readings  per  day  of  the  head 
on  a  weir  may  give  an  erroneous  result,  especially  when  the 
stream  is  subject  to  fluctuation.  To  properly  obtain  the  mean 
head  on  the  weir  for  the  24-hour  period  an  automatic  register 
should  be  installed  a  sufficient  distance  above  the  crest  of  the 
weir  to  avoid  the  effects  due  to  the  curvature  of  the  approach- 
ing water. 


WATER    STAGE    REGISTERS  81 

8.  WHERE  THE  AVAILABLE  GAGE  READERS  DO  NOT  HAVE 
SUFFICIENT  INTELLIGENCE  TO  READ  A  GAGE   OR   CAN   NOT   BE 

TRUSTED. 

9.  WHERE  THE  STATION  is  SITUATED  AT  AN  ISOLATED 

POINT  AND  A  GAGE  READER  IS, NOT  AVAILABLE. 

The  necessity  for  establishing  a  station  at  an  isolated 
point,  where  a  gage  reader  is  not  available,  has  caused  the  in- 
stallation of  many  automatic  registers.  Many  stations  are  50 
to  100  miles  from  a  railroad  in  regions  whose  inhabitants 
have  no  fixed  abode.  This  condition  affects  the  collection  of 
data  for  irrigation  projects  less  than  for  water  powers.  Irri- 
gation lands  are  in  general  not  so  remote  from  habitations  as 
water  power  sites.  At  several  stations  in  the  West  valuable 
stream  flow  data  could  not  have  been  collected  had  the  contin- 
uous automatic  water  stage  register  not  been  invented. 


ESSENTIAL  FEATURES  OF  AUTOMATIC 
WATER  STAGE  REGISTERS 

Automatic  recording  water  stage  registers  consist  of: 

(1)  A  float  that  rises  and  falls  with  the  surface  of  the 
water. 

(2)  A  mechanism  that  transfers  the  vertical  motion  of 
the  float  to  the  record,  either  in  natural  or  reduced  scale. 

(3)  A  sheet  of  paper  on  which  a  record  of  the  rise  and 
fall  of  the  float  is  made. 

(4)  A  clock. 

(5)  A  cover  for  the  instrument. 

The  essential  features  of  a  good  automatic  register  are: 

(1)  A  float  of  sufficient  area  to  be  sensitive  enough  to 
respond  quickly  to  a  change  in  water  stage,    connected    to    a 
counterweight  by  means  of  a  perforated  band  that  is  positive 
in  its  action. 

(2)  A   transfer  mechanism   so   carefully   made   that   it 
performs  all  of  its  functions  with  certainty  and  precision. 

(3)  A  record  sheet  that  is  not  distorted  by  moisture  and 
that  gives  the  record  in  a  form  most  appropriate  to  the  use  to 
which  it  is  to  be  put.     This  involves  the  cost  of  handling  the 
records,  including  provision  for  filing  them,  and  of  the  office 
work    incident   to    applying    the  gage  heights  to  the  discharge 
table. 


82  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

(4)  A  weight  driven  clock,  of  heavy  yet  simple  con- 
struction, with  a  refined  escapement,  compensated  for  tempera- 
ture. 

THE  FLOAT 

The  value  of  records  from  water  stage  registers  varies 
with  their  accuracy,  which  is  limited  in  large  measure  by  the 
readiness  with  which  the  instrument  responds  to  slight  changes 
in  the  height  of  water.  Precision  in  recording  depends  directly 
on  the  amount  of  power  required  to  operate  that  part  of  the 
mechanism  which  records  the  water  stage  at  any  given  instant, 
as  well  as  upon  the  time  element.  This  power  is  obtained  from 
the  bouyant,  or  lifting  force,  of  the  water  acting  on  the  area 
of  a  float,  that  is  connected  by  means  of  a  perforated  band  to 
a  counterweight.  The  band  passes  over  the  driving  wheel  of 
the  recording  mechanism  between  the  float  and  the  counter- 
weight. The  band  itself  should  be  as  light  in  weight  as  pos- 
sible, consistent  with  its  required  strength  and  life.  The 
counterweight  should  weigh  somewhat  more  than  the  total 
weight  of  the  band  and  a  weight  sufficient  to  overcome  the 
friction  of  the  instrument,  if  suspended  from  the  counterweight 
side  of  the  driving  pulley  of  the  recording  mechanism.  Like- 
wise, the  float  should  weigh  somewhat  more  than  the  combined 
weights  of  the  tape,  the  counterweight  and  a  weight  sufficient 
to  overcome  the  friction  of  the  instrument  if  suspended  from 
the  float  side  of  the  driving  pulley. 

The  cross-sectional  area  of  the  float  parallel  to  the  water 
surface  determines  the  power  of  flotation,  the  readiness  of 
response  to  slight  variations  in  water  stage,  and  the  amount  of 
power  available  to  operate  the  recording  mechanism.  The 
area  of  the  float  parallel  to  the  water  should  be  as  large  as  pos- 
sible in  order  to  get  a  maximum  amount  of  displacement,  and 
hence  bouyancy  and  power,  for  each  fraction  of  an  inch  of  the 
vertical  height  of  the  float. 

When  an  instrument  is  installed  over  the  well,  the  float 
and  counterweight  together  with  the  bouyant  force  of  the 
water,  will  assume  a  relation  of  balance  or  equilibrium;  that 
is,  the  weight  of  the  counterweight  and  band  on  its  side  of  the 
driving  wheel  will  equal  the  combined  weight  of  that  portion 
of  the  float  that  is  above  the  water  surface  and  the  band  on  the 


WATER    STAGE    REGISTERS  83 

float  side  of  the  driving  pulley.  If  no  power  was  required  to 
operate  the  instrument,  then  a  condition  of  balance  would  al- 
ways be  established  immediately  after  any  change  in  the 
elevation  of  the  water  surface  and  the  driving  wheel  would 
turn  an  amount  equal  to  the  change  in  rise  and  fall. 

Since  it  is  impossible  to  construct  a  frictionless  instru- 
ment, or  in  other  words,  one  that  would  require  no  power  to 
operate,  it  is  necessary  to  provide  the  required  power.  That  is 
done  by  disturbing  the  relation  of  balance  between  the  float 
and  the  counterweight,  mentioned  above,  by  an  amount  equal 
to  a  weight  sufficient  to  drive  the  recording  mechanism.  The 
overbalance  is  due  to  the  rise  or  fall  of  the  water  around  the 
float,  and  the  instrument  will  not  respond  until  such  rise  or 
fall  of  the  water  on  the  float  forms  a  water  column  of  the  cross- 
sectional  area  of  the  float  and  equal  in  weight  to  the  force  re- 
quired on  the  rim  of  the  driving  wheel  to  operate  the  instrument. 
It  will  readily  be  seen  that  for  a  given  weight  the  altitude  of 
this  water  column,  (which  is  the  rise  or  fall  of  the  water  sur- 
face) must  be  greater  for  a  small  cross-sectional  area  than  for 
a  large  cross-sectional  area.  Hence  the  same  instrument  will 
be  more  sensitive,  with  a  corresponding  increase  in  the  refine- 
ment in  the  record,  when  a  large  float  is  used  than  when  a 
small  one  is  used. 

Since  the  area  of  the  float  parallel  to  the  water  controls 
the  sensitiveness  of  the  register,  it  is  interesting  to  note  the 
following  comparison  of  the  weights  of  circular  columns  of 
water  one  hundredth  of  a  foot  (0.12")  high  for  various  diame- 
ters. These  computations  show  the  relative  power  derived  from 
floats  of  different  diameters.  It  will  be  noted  that  the  power 
of  the  float  varies  as  the  square  of  its  diameter. 

Diameter  of  Areaoffloa,         Inches  Volume  of     S^ o'f  weigSwlr 

float  in  square  in  water  column         water  column  in 

in  inches  inches  1/1000  foot    in  cubic  ins.       in  ounces  ounces 

4  12.57         xO.12         1.51         0.58  0.88 

6  28.27  0.12         3.39         0.58  1.97 

8  50.26  0.12         6.03         0.58  3.50 

10  78.54  0.12         9.43         0.58  5.47 

In  Gurley  water  stage  registers  the  power  required  to  op- 
erate the  recording  mechanism  is  reduced  to  a  minimum,  but 
to  insure  precision  and  certainty  of  action  a  large  float  is 
always  used. 


84  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

THE  TRANSFER  MECHANISM 

The  range  of  the  time-keeping  mechanism  may  be  defin- 
itely decided  upon  for  any  type  of  register.  Hence,  if  the 
movement  along  either  axis  of  the  register  must  be  limited  the 
time  axis  may  be  of  fixed  length.  Such  is  the  case  in  Gurley 
registers  of  the  graphic  type,  on  which  the  records  are  changed 
at  fixed  intervals  of  time.  On  printing  type  registers,  however, 
the  time  is  transferred  to  the  record  from  the  faces  of  cylindri- 
cal type  wheels,  which  revolve  with  the  hands  of  the  clock  con- 
tinuously for  as  long  a  time  as  may  be  desired. 

The  range  of  water  stage,  on  the  other  hand,  may  be  decid- 
edly variable.  Hence,  on  graphic  registers  the  axis  along 
which  the  record  of  stage  is  made  should  not  be  limited  in  length. 
For  this  reason  the  record  of  stage  should  be  made  around  the 
circumference  of  the  cylinder  on  the  register.  Since  it  is  possible 
for  the  cylinder  to  revolve  on  its  axis,  such  an  arrangement  of 
the  axis  of  the  record  allows  any  change  of  stage,  no  matter 
how  great,  to  be  recorded,  each  complete  revolution  of  the  cyl- 
inder corresponding  to  a  definite  change  in  stage.  On  the 
printing  type  registers  the  record  of  stage  is  printed  on  the 
continuous  record  tape  by  cylindrical  type  wheels,  and  these 
are  made  so  that  they  may  make  any  necessary  number  of 
complete  revolutions. 

All  parts  of  the  transfer  mechanism,  including  the  lead 
screws  that  move  the  pencil  carriage,  the  perforated  bronze 
band  connecting  the  float  and  the  driving  pulley,  and  all  gears, 
should  be  so  accurately  constructed  as  to  be  free  from  lost 
motion. 

THE  RECORD  SHEETS 

Record  sheets  for  graphic  registers  should  have  accurately 
printed  on  them  a  time  scale  and  a  water  stage  scale.  The  point 
of  the  pencil  is  the  index  for  time  and  water  stage  when  adjusting 
the  record  sheets.  These  record  sheets  are  shown  on  pages 
116  and  117. 

The  record  sheet,  for  printing  type  registers,  is  a  strip  of 
paper  \^A  inches  wide,  a  roll  of  which  is  placed  on  one  reel  and 
received  on  another,  after  having  passed  over  the  tvpe  wheels 
where  it  has  printed  upon  it  the  water  stage  to  hundredths  of  a 
foot  and  the  time  of  record.  Between  the  record  paper  and  the 
type  wheels  runs  a  strip  of  carbon  paper  the  same  width  as  the 


WATER    STAGE    REGISTERS  85 

record  paper  and  carried  in  the  same  manner  between  the  type 
wheels  and  the  record  paper,  the  carbon  face  being  next  to  the 
record  paper.  When  the  printing  hammer  strikes,  a  carbon 
impression  is  made  on  the  white  record  paper. 

The  printed  type  of'  record  has  these  advantages :  the  re- 
lation of  time  and  gage  height  is  in  no  way  affected  if  moisture 
changes  the  width  or  length  of  the  tape,  and  it  is  a  kind  of 
record  that  may  be  understood  by  commissioners  or  attorneys 
without  engineering  training. 

THE  CLOCK 

A  weight  driven  clock  compensated  for  temperature  is  the 
most  desirable  type  of  time  keeper  for  a  water  stage  register. 
In  order  to  get  extra  long  bearings  for  the  shafts  of  the  clock 
gears  the  front  and  back  plates  of  the  clock  should  be  heavier 
than  in  an  ordinary  time  piece.  The  lower  wheels  that  carry 
the  heavy  weights  should  be  fitted  with  phosphor  bronze  bush- 
ings and  the  shafts  themselves  should  be  of  highly  polished 
steel,  these  metals  being  the  most  suitable  combination  for  such 
purposes.  The  adjustment  of  the  mesh  between  the  escapement 
and  the  clock  train  should  be  perfect.  This  relation  is  per- 
manently maintained  by  hardening  the  end  of  the  escapement 
shaft  and  using  a  sapphire  bearing  jewel.  The  escapement 
must  be  so  arranged  that  it  may  be  thrown  out  of  mesh  with  the 
clock  train  to  make  it  possible  to  set  the  clock  to  the  proper 
time  without  changing  the  relation  between  the  time  type  wheel 
(5),  the  clutch  (11),  and  the  hands.  (See  Fig.  47,  page  91) . 

THE  COVER 

A  tight  fitting  cover  should  enclose  all  automatic  recording 
registers  so  as  to  exclude  dirt  from  the  mechanism.  Dust  or 
grit  settling  on  the  gears  and  bearings  of  any  time  piece  soon 
interferes  with  its  satisfactory  operation. 

TYPES  OF  GURLEY  AUTOMATIC  WATER 
STAGE  REGISTERS 

Gurley  automatic  water  stage  registers  are  divided  into 
two  classes  —  those  making  a  printed  record,  and  those  making 
a  graphic  record.  In  the  printing  type  a  simultaneous  record 
of  water  stage  and  time  is  made ;  in  the  graphic  type  the  record 
is  made  continuously,  by  a  curve,  the  coordinates  of  which  in- 
dicate the  time  and  the  stage.  Both  classes  of  registers  will  be 
described  in  detail. 


86  W.    &L.  E.  GURLEY,  TROY,  N.  Y. 

Gurley  Printing  Water  Stage  Register 

Range,  0  to  36.99  feet  without  repeating. 

Prints  at  15,  30  or  60  minute  intervals. 

The  time  that  the  clock  will  run  depends  upon 

the  depth  of  the  well. 

The  fall  of  clock  weight  is  1  "*/?,  inches  per  day. 
Patented  January  10,  1911. 

The  difficulty  of  scaling  with  precision  the  records  made 
by  a  graphic  register,  the  tendency  of  the  paper  to  be  affected 
by  moisture  or  other  causes,  and  the  limited  time  for  which 
the  record  can  be  taken,  have  led  to  our  introducing  a  register 
•which  prints  on  a  continuous  paper  strip,  at  intervals  of  15, 
30,  or  60  minutes,  the  height  of  the  water  in  feet  and  hundredths 
of  a  foot  for  a  period  of  time  dependent  on  the  range  of  fall 
allowed  the  driving  weights,  which  move  at  the  rate  of  1%  inches 
for  a  period  of  24  hours. 


FIG.  43. —  Section  of  Paper  Tape,  showing  Printed  Record 
made  on  a  No.  630  Printing  Register. 

This  register  is  the  result  of  years  of  study  and  experiment, 
and  is  made  in  the  best  manner  and  of  the  best  material,  has 
had  the  original  inspection  and  approval  of  some  of  the  most 
eminent  hydraulic  engineers,  and  has  been  tested  under  severe 
conditions  of  actual  service  with  most  satisfactory  results.  We, 
therefore,  have  no  hesitation  in  recommending  its  use  to  all 
who  require  accuracy  and  efficiency  in  water  measurements. 

ADVANTAGES  OF  GURLEY  PRINTING  REGISTERS 

Certainty  of  operation.  These  registers  have  been  devel- 
oped to  meet  actual  field  conditions  and  are  performing  with 
certainty  and  without  interruption  in  many  places  and  under  a 
great  variety  of  physical  conditions. 


WATER    STAGE    REGISTERS 


87 


FIG.  44. —  No.  630  Printing  Water  Stage  Register. 

Front  view,  showing  clock,  float  and  weights. 

Range,  0  to  36.99  feet  without  repeating. 


88  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

Frequency  of  record  of  stage  and  time.  This  is  the  only 
register  that  records  automatically  a  printed  record  of  stage  to 
hundredths  of  a  foot  and  of  time  to  fractions  of  an  hour. 

Continuity  of  record.  This  register  will  operate  contin- 
uously as  long  as  the  clock  weight  which  is  lowered  IK  inches 
in  24  hours  is  free  to  fall  in  the  well.  Registers  have  frequently 
operated  for  six  months  with  one  winding.  The  driving 
weights  may,  however,  be  raised  whenever  required  without 
moving  the  cover  or  in  any  way  interfering  with  the  operation 
of  the  register. 

Absence  of  moisture  effects.  The  record  is  made  by 
printing  figures  on  a  strip  of  paper  and  is  independent  of  the 
size  of  the  strip.  The  accuracy  of  the  record  is  unaffected  by 
any  changes  in  the  size  of  the  strip  of  paper  due  to  varying 
conditions  of  moisture. 

Unlimited  record  of  stage.  A  change  of  stage  is  recorded 
by  means  of  the  revolution  of  the  type  wheels  of  the  recording 
mechanism.  These  are  free  to  revolve  any  number  of  times 
with  the  change  in  stage  and  may  do  so  without  confusing 
the  record. 

Singleness  of  interpretation  and  permanence  of  record. 
The  record  of  both  time  and  stage  is  printed  directly  on  the 
record  paper  in  permanent  form.  Printed  figures  have  only 
one  meaning  and  hence  the  interpretation  of  the  record  is  not 
susceptible  to  any  variation  due  to  personal  equation.  These 
considerations  are  of  great  importance  where  the  figures  are 
likely  to  become  part  of  a  court  record. 

Convenience  in  changing  records.  The  record  papers 
may  be  changed  at  any  time.  It  is  not  necessary  to  change 
them  at  stated  intervals.  This  makes  possible  the  use  of  this 
type  of  register  in  inaccessible  places. 

Simplicity  of  record.  The  printed  record  is  a  form 
easily  interpreted  by  those  without  technical  training.  The 
reduction  of  the  record  is  a  non-technical  clerical  operation. 
It  is  greatly  facilitated  by  the  use  of  a  tape  reel.  (See  Fig.  46) . 

Superior  mechanical  execution.  Every  part  is  made  of 
properly  selected  material  finely  finished  to  insure  accuracy 
in  operation. 


WATER    STAGE    REGISTERS 


89 


FIG.  45.— No.  630  Printing  Water  Stage  Register. 
Side  vietv,  showing  paper  reels,  type  wheels  mid  cushioned  hammer. 


90 


W.  &  L.  E.  G  U  R  L  E  Y,  TROY,  N.  Y. 


FIG.  46. —  No.  632  Tape  Reel,  for  use  with 
No.  630  Printing  Register. 

For  convenience  in  handling  and  examining  records  on  the 
printed  tape,  a  Tape  Reel  is  provided,  as  shown  above.  The 
tape  is  wound  upon  a  storage  spool,  or  may  be  passed  from 
one  spool  to  another  over  a  table,  under  a  thin  metal  plate 
through  an  opening  in  which  the  figures  on  the  tape  may  be 
observed,  and  such  notations  as  are  desired  made  upon  it  while 
it  is  wound  from  one  spool  to  the  other. 

CONSTRUCTION  OF  GURLEY  PRINTING  REGISTERS 

A  base  (1)  about  14  inches  square,  (See  Figs.  47,  48  and 
49),  at  either  corner  of  which  is  a  rod  (2)  22%  inches  long 
supporting  a  top  (3),  forms  a  frame  for  the  register.  On  the 
base  (1)  extending  to. top  (3)  is  the  back  frame  (4)  which 
supports  the  clock,  paper  reels,  sprocket,  and  type  wheels. 

The  recording  mechanism  consists  of  three  parallel  type 
wheels,  viz. — the  time  wheel  (5),  the  even  foot  wheel  (6),  and 
the  hundredth  of  foot  wheel  (7),  on  the  face  of  which  are  raised 
figures  and  divisions  indicating,  respectively,  the  period  of  time 
from  one  to  twelve  hours,  divided  into  intervals  of  15  minutes; 
the  number  of  feet  from  0  to  36;  and  the  hundredths  of  a  foot 


WATER    STAGE    REGISTERS 


91 


FIG.  47. —  No.  630  Printing  Water  Stage  Register. 

from  0  to  100.  If  the  water  should  rise  above  this  height,  no 
trouble  will  be  experienced  in  determining  the  stage  of  the 
water. 

The  type  wheel  indicating  time  (5)  is  controlled  by  a 
weight  driven  clock  of  finest  construction,  and  with  full  jewelled 
escapement  (9)  which  is  compensated  to  endure  variations  of 


92  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

temperature  without  variation  in  its  regular  operation.  The  es- 
capement is  protected  by  a  dust  cover  (15)  which  is  transparent. 
The  escapement  may  be  disengaged  from  the  clock  train  by  the 
use  of  the  nut  (12),  the  spring  (13),  and  the  milled  head 
screw  (14). 

The  weight  driven  clock  is  very  simple  in  construction, 
extra  heavy,  beautifully  made,  the  end  of  the  shaft  next  to  the 
escapement  being  hardened  and  having  a  sapphire  bearing 
with  what  is  called  the  "olive  hole."  This  care  reduces  the 
retarding  effect  of  the  thickening  of  the  oil  to  a  minimum,  and 
is  taken  so  that  the  mesh  of  the  escapement  is  always  in  the 
same  relation  with  the  wheel  on  the  escapement  shaft.  The 
escapement  is  fully  jewelled  and  has  a  compensating  balance 
wheel.  Thus  the  clock  will  run  uniformly  in  heat  and  cold. 

When  a  clock  movement  is  subjected  to  cold,  the  hair 
spring  contracts  and  becomes  stronger.  The  steel  rim  and 
penter  of  the  balance  contracts,  as  does  also  the  brass  rim;  but 
as  the  brass  rim  contracts  more  than  the  steel  rim,  it  has  the 
effect  of  straightening  the  rim — thus  increasing  the  diameter 
of  the  wheel,  and  carrying  the  mass  of  its  weight  further  away 
from  the  axis,  which  has  a  retarding  effect. 

The  clock  is  rigidly  supported  by  the  back  frame  (4)  and 
the  front  left  hand  corner  rod  (2).  It  has  a  thrust  brace  (16) 
and  an  adjusting  screw  (17).  The  driving  wheel  of  the  clock 
train  (18)  is  on  a  shaft  (19)  which  is  supported  in  ball  bear- 
ings by  the  two  standards  (20)  and  (21).  On  the  shaft  (19) 
is  a  loose  sprocket  wheel  and  a  ratchet  wheel  (22)  that  drives 
the  clock  train  with  a  pawl  and  spring  working  on  the  driving 
gear  wheel.  The  clock  weight  hangs  on  one  end  of  a  chain 
(54)  that  passes  over  the  sprocket  wheel  (22). 

The  clock  will  run  continuously  for  a  length  of  time 
depending  on  the  depth  of  the  well,  the  weight  falling  1% 
inches  in  24  hours.  Registers  have  frequently  operated  for  six 
months  with  one  winding.  The  clock  weight  may  be  raised 
whenever  required,  without  moving  the  cover  or  in  any  way 
interfering  with  the  operation  of  the  register. 

Four  reels,  mounted  on  the  main  standard  of  the  instru- 
ment, carry  and  receive  the  paper  strip  and  the  carbon  backing. 
A  strip  of  paper  two  feet  long  and  I1/!  inches  wide  is  all  that 
is  required  for  the  ninety-six  impressions  made  in  twenty-four 


WATER    STAGE    REGISTERS 


93 


50 


FIG.  48. —  No.  630  Printing  Water  Stage  Register. 


94  W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

hours.     Moisture  has  no  effect  on  the  record,  which  is  printed 
directly  on  the  paper. 

The  carbon  paper  is  supplied  from  reel  (23)  and  the  record 
paper  from  reel  (24).  Both  strips  pass  over  the  type  wheels 
(5,  6,  and  7),  the  carbon  face  against  the  white  record  paper, 
and  the  carbon  strip  is  then  received  on  reel  (25)  and  the 
printed  record  paper  on  reel  (26).  Both  strips  are  held  taut 
by  the  tension  of  a  weight  (56)  (See  Fig.  49)  attached  to  a 
chain  (55)  that  passes  over  the  sprocket  wheel  (27).  This 
sprocket  wheel  also  has  a  ratchet  wheel  attached  to  it,  which  is 
engaged  by  a  pawl  and  spring  working  on  a  flange  wheel  (28) 
fastened  to  a  shaft  (29)  and  carried  in  ball  bearings  by  two 
standards  (30  and  31) ;  fastened  to  shaft  (29)  is  a  gear  wheel 
(32)  which  is  in  mesh  with  a  train  of  gears  connecting  with  the 
receiving  reels  (25  and  26).  A  locking  device  (33)  is  pro- 
vided to  lock  this  train  of  gears  when  taking  the  record  off  the 
instrument. 

The  two  type  wheels  indicating  water  stage  (6  and  7)  are 
moved  by  a  sprocket  wheel  (8),  connected  to  the  float  and 
counterweight  (51)  by  a  perforated  phosphor  bronze  band 
(47),  so  that  any  change  in  the  water  stage  is  immediately  in- 
dicated by  a  corresponding  movement  of  the  type  wheels  (6 
and  7).  See  Fig.  47. 

The  hammers,  one  for  the  time  (45),  one  for  the  even 
foot  (44),  and  one  for  the  hundredth  of  a  foot  (37)  are  pivoted 
on  a  shaft  (34),  one  end  of  which  is  carried  by  the  back  frame 
(4)  and  the  other  by  a  standard  (35).  The  lower  ends  of  the 
hammers  are  weighted  and  the  upper  ends  have  a  cushioned 
face  (36).  Attached  to  the  side  of  the  hundredth  hammer  (37) 
is  a  roller  and  holder  (38)  which  travel  in  a  saw  tooth  cam 
(39).  The  number  of  teeth  on  the  cam,  one,  two,  or  four,  de- 
pends on  the  time  interval  desired  between  successive  printings 
of  the  record.  The  cam  moves  with  the  clock  and  pushes  the 
hammers  back  until  the  point  of  the  cam  passes  the  holder  (38) 
whereupon  the  hammers  fall,  allowing  the  cushioned  face  (36) 
to  strike  a  blow  on  the  record  paper  and  its  carbon  backing 
covering  the  type  wheels  (5,  6,  and  7)  thus  printing  the  time 
and  height  of  water  on  the  paper  record.  The  points  of  the 
cam  are  made  of  hardened  steel,  to  always  insure  a  sharp  edge 
where  the  hammer  drops  from  the  cam. 


WATER    STAGE    REGISTERS 


95 


FIG.  49. —  Details  of  Installation  of  No.  630  Printing  Register. 

The  register  as  above  described,  when  in  use  is  covered 
by  a  metal  hood  (40)  fitting  tightly  at  the  bottom  on  a  rubber 
gasket  (41),  and  having  at  the  top  a  screw  nut  (42),  which  may 
be  secured  by  a  lock  through  the  slot  (43)  to  prevent  removal 
of  the  case  by  unauthorized  persons.  The  face  of  the  clock 


96          W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

may  be  seen  through  a  glass-covered  opening  in  the  metal  hood, 
and  the  clock  may  be  wound  from  the  outside  by  lifting  the 
weight  by  one  hand  and  pulling  the  driving  chain  with  the  other 
at  such  intervals  as  required,  without  the  removal  of  the  case 
or  disturbance  of  the  instrument.  The  paper  mechanism  may 
be  wound  in  a  similar  manner. 

The  large  diameter  of  the  copper  float,  10  inches,  enables 
it  to  respond  immediately  to  any  variations  in  the  height  of 
the  water,  the  slightest  change  being  recorded.  Its  size  and 
shape  render  it  extremely  sensitive,  and  the  top  is  rounded  so 
that  foreign  matter  cannot  lodge  on  it  and  change  the  degree 
of  immersion. 

The  instrument  is  made  of  metal  throughout  and  is  of  the 
highest  grade  of  mechanical  construction,  which  insures 
accuracy  in  operation. 

INSTALLATION    AND    OPERATION    OF    GURLEY 
PRINTING  REGISTERS 

An  appropriate  shelter*  for  the  register  is  required  at 
each  station.  The  door  and  windows  of  the  shelter  should  be 
closed  while  making  adjustments,  if  the  wind  is  blowing. 

The  box  in  which  the  instrument  is  shipped  with  the  pack- 
ing material  in  it  should  be  kept  at  hand  in  case  it  is  desired 
to  ship  the  register  to  another  gaging  station  at  some  later  time. 

Before  moving  the  metal  cover  of  the  register,  the  house 
should  be  swept  clean.  The  mechanism  of  the  register,  like 
that  of  any  other  high  grade  clock,  should  be  protected  from 
dust  whenever  the  cover  is  taken  off.  The  cover,  when  removed 
from  the  gage,  should  be  set  down  in  a  clean  place,  otherwise 
it  will  carry  dust  to  the  register.  The  necessary  openings 
through  the  gage  table  and  floor  of  the  shelter  may  be  located 
properly  by  using  the  template,  which  is  sent  with  each  instru- 
ment for  that  purpose.  When  the  holes  have  been  bored,  place 
the  register  on  the  gage  table,  take  off  the  metal  cover  (40) 
and  put  the  four  wood  screws  through  the  holes  (46)  into  the 
gage  table.  Then  remove  carefully  from  the  parts  of  the  regis- 
ter the  packing  used  to  protect  the  mechanism  during  shipment. 

Find  the  exact  stage  of  water  in  the  well  by  reading  the 
hook  or  other  fixed  gage.  Then  revolve  the  sprocket  wheel  (8) 

*See  U.  S.  Geological  Survey,  Water  Supply  Paper  No.  371. 


WATER    STAGE    REGISTERS  97 

until  the  foot  mark  on  the  middle  type  wheel  (6),  correspond- 
ing to  the  foot  mark  on  the  hook  gage,  is  opposite  the  center  of 
the  hammer.  Continue  to  revolve  the  sprocket  wheel  (8)  until 
the  hundredth  mark  on  the  "type  wheel  (7),  corresponding  to 
the  hook  gage  reading,  is  correctly  in  line  with  the  center  of  the 
foot  figure  which  is  always  the  index. 

Attach  the  perforated  band  (47)  to  the  clamp  (48)  on 
top  of  the  float  and  let  the  float  down  into  the  well  through  the 
trap  door  in  the  floor  of  the  shelter,  allowing  the  perforated 
band  to  unwind,  like  thread  from  a  spool,  and  being  careful 
that  it  does  not  kink.  Pass  the  end  of  the  band  upward  through 
the  slot  in  the  floor  and  the  proper  hole  in  the  table  and  through 
slot  (49)  in  the  base  of  the  register.  Bring  the  band  over  the 
sprocket  wheel,  but  do  not  let  the  metal  band  come  in  contact 
with  the  previously  adjusted  sprocket  wheel,  and  pass  it  down 
through  the  slot  (50)  in  the  base  of  the  machine.  Through  one 
of  the  holes  in  the  band  put  an  adjusting  pin,  so  that  it  will  rest 
across  the  slot  (50)  and  prevent  the  metal  band  pulling  over 
the  sprocket  wheel.  Allow  sufficient  length  of  tape  below  the 
floor  so  that  the  float  may  freely  drop  the  full  depth  of  the  well. 
Then  attach  the  counterweight  (51)  to  the  metal  band.  Take 
the  pin  out  of  the  bronze  band,  and  having  the  band  taut  on 
the  float  side,  lower  the  counterweight  slowly,  and  carefully 
fit  the  perforated  band  over  the  spines  on  the  sprocket  wheel. 
Compare  the  figures  on  the  type  wheels  (6  and  7)  with  the 
exact  stage  of  the  water  in  the  well  and  if  they  disagree  with 
the  water  stage  reading,  having  moved  a  small  amount  when 
the  perforations  of  the  band  were  fitted  to  the  spines,  this  small 
variation  may  be  corrected  and  the  figures  brought  to  the  cor- 
rect reading  by  opening  clamp  (48),  thus  changing  the  length 
of  the  perforated  band.  After  making  this  adjustment,  tighten 
the  two  clamp  screws.  Before  raising  the  float  to  make  this 
correction,  put  an  adjusting  pin  through  the  tape  across  the 
slot  in  the  base  on  the  counterweight  side,  so  that  the  weight 
will  not  drop  suddenly.  Rapid  revolution  of  the  sprocket  may 
damage  the  mechanism  that  changes  from  one  foot  mark  to 
another  on  the  type  wheel,  because  this  mechanism  is  so  con- 
structed that  it  works  extremely  fast  under  normal  operating 
conditions.  Once  the  metal  band  is  adjusted  it  will  hold  its 
adjustment  indefinitely. 


98          W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

The  clock  in  the  register  is  shipped  with  the  escapement 
(9)  out  of  mesh  with  the  clock  train.  To  set  the  clock  to  the 
correct  time,  turn  the  large  gear  (53)  between  the  clock  plates, 
so  that  the  hands  will  move  in  a  clockwise  direction.  Do  not 
touch  the  hands.  Loosen  the  milled  head  nut  (12)  on  the  in- 
side of  the  front  plate  of  the  clock;  then  turn  the  milled  head 
screw  (14)  on  the  right  hand  edge  of  the  front  plate,  until  it 
comes  to  a  stop,  but  do  not  force  it,  and  the  escapement  will 
then  be  in  mesh  with  the  clock  gears.  Tighten  the  milled  head 
nut  (12)  gently.  Next  place  the  chain  over  the  sprocket  wheel 
(22)  under  the  clock,  and  hang  the  heavy  clock  weight  on  the 
end  of  chain  (54)  on  the  left  side  of  the  sprocket  wheel. 
When  hanging  the  weight  on  the  chain,  lower  the  weight  gently 
in  order  not  to  damage  the  winding  mechanism.  When  wind- 
ing the  clock,  use  the  left  hand  to  raise  the  weight,  and  the 
right  hand  to  pull  down  the  right  hand  end  of  the  clock  chain. 

A  locking  device  (10)  on  the  back  frame  of  the  clock  is 
used  to  keep  the  weight  from  falling  when  the  escapement  is 
thrown  out  of  mesh  with  the  clock  train.  In  locking  the  clock 
train  do  not  force  the  lever  on  the  tops  of  the  gear  teeth,  or  the 
bearing  on  the  gear  shaft  may  be  damaged.  Before  throwing 
the  escapement  out  of  mesh,  always  lock  the  clock  train  if  the 
weight  is  on  the  clock.  The  escapement  would  be  badly  dam- 
aged should  the  gear  run  at  high  speed  just  as  it  was  leaving 
the  teeth  on  the  pinion  of  the  escapement. 

When  adjusting  the  clock,  with  the  escapement  out  of  mesh 
and  the  weight  on  the  chain,  hold  the  upper  large  gear  (53)  of 
the  clock  with  the  left  hand  and  unlock  the  train  with  the  right; 
then  allow  the  clock  train  to  revolve  until  the  hands  indicate 
the  correct  time.  Use  the  left  hand  as  a  brake  and  almost  slop 
the  clock  just  before  the  high  part  of  the  cam  reaches  the  roller 
on  the  hammer,  and  immediately  after  it  passes.  This  method 
must  be  followed  exactly,  or  else  the  small  roller  will  strike 
the  cam,  be  damaged,  and  forced  out  of  adjustment. 

Registers  are  shipped  from  the  factory  with  the  white 
record  paper  and  the  carbon  paper  in  place  and  properly 
threaded  around  the  type  wheels.  The  weights  on  the  paper 
winding  mechanism  should  be  hung  in  the  same  careful  manner 
as  the  clock  weights.  To  wind  the  paper  mechanism,  use  the 


WATER    STAGE    REGISTERS  99 

left  hand  to  raise  the  weight  and  the  right  to  pull  down  the  right 
hand  end  of  the  paper  chain. 

The  locking  device  on  the  back  frame  of  the  register  should 
be  used  whenever  the  paper  is  being  put  on  or  taken  off  the 
instrument.  If  the  gear  train  is  not  locked  before  taking  off 
the  paper  the  weight  will  drop  into  the  well. 

When  the  record  is  changed,  about  a  foot  of  white  paper 
should  be  left  beyond  the  last  printed  record  for  facility  of 
handling  in  the  office,  as  well  as  for  notes  made  at  the  time  of 
removal  to  show  the  time  and  hook  gage  reading.  Both  the 
white  and  the  carbon  papers  should  be  removed  when  changing 
the  record. 

To  change  the  record,  lock  the  gear  train  and  remove  the 
large  round  nuts  on  reels  (25  and  26),  and  then  remove  the 
side  plates  of  the  receiving  spools.  This  may  be  done  by  turn- 
ing the  large  round  nuts  to  the  left,  being  careful  not  to  let 
them  drop  when  they  are  completely  unscrewed  from  the  reel 
hub.  Do  not  remove  the  small  hexagonal  nuts  on  the  reels 
(25  and  26)  from  the  end  of  the  shaft  while  the  paper  weight 
is  on  the  chain,  because  the  gears  of  the  train  might  become 
disengaged  and  thereupon  the  weight  would  drop. 

After  taking  both  spools  of  paper  from  the  receiving  rolls 
(25  and  26),  press  the  paper  tubes  onto  the  reel  pins  and  bring 
the  strip  of  carbon  paper  over  the  type  wheels  and  around  the 
under  side  of  spool  (25) .  Attach  it  to  the  circumference  of  the 
paper  tube  by  means  of  a  short  piece  of  gummed  paper,  leaving 
enough  carbon  paper  to  make  two  or  three  turns  around  the 
paper  spool.  Release  the  locking  device  (33),  whereupon  the 
mechanism  will  take  up  the  slack  in  the  carbon  paper  which  will 
sustain  the  weight  (56).  Place  the  white  paper  over 
the  type  wheels  and  over  the  upper  right  hand  receiving  spool 
(26),  being  sure  that  the  pins  on  the  time  type  wheels  perforate 
the  white  paper  also.  Press  a  paper  tube  on  the  pins  of  this 
reel  and  fasten  the  end  of  the  white  paper  to  the  circumference 
of  the  paper  spool  with  gummed  paper,  having  the  white  paper 
taut.  Take  care  to  see  that  both  strips  of  paper  have  the  same 
tension  between  the  type  wheels  and  the  receiving  reels,  and 
that  both  strips  of  paper  are  close  to  the  flange  of  the  time  type 
wheel.  Replace  the  side  plates  on  the  receiving  reels  and  put 
on  the  round  nuts. 


100         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

It  will  be  necessary  to  oil  and  clean  the  bearings  on  the 
instrument  only  once  a  year,  with  the  exception  of  the  two  lower 
bearings  on  the  clock  plates  and  the  small  roller  on  the  ham- 
mer; and  these  should  have  a  drop  of  oil  once  in  three  months. 
To  oil  the  instrument,  use  only  the  best  watch  oil  that  is  sent 
with  it,  and  which  will  prevent  the  instrument  from  sticking  in 
extreme  cold  weather.  The  oil  should  be  applied  carefully  to 
the  bearings,  using  a  wire  for  that  purpose.  Never  apply  oil 
to  the  teeth  of  any  of  the  clock  gears  except  (18)  which  may  be 
oiled  with  a  good  oil. 

The  lower  bearings  in  the  clock  frame  are  covered  with 
small  caps  having  oil  holes  on  the  upper  side.  The  bearings 
above  have  no  oil  holes  or  caps,  so  that  the  drop  of  oil  should 
be  put  on  the  shaft  next  to  the  bearings.  The  internal  mechan- 
ism of  the  type  wheels  should  be  oiled  once  a  year,  but  it  is 
not  necessary  to  take  the  type  wheels  apart  to  clean  or  oil  them. 
When  oiling  the  type  wheel  gears,  remove  the  white  and  carbon 
papers  from  them  and  place  a  cloth  under  the  wheels  to  catch 
any  surplus  oil  that  may  run  down  between  them.  Also  take 
the  perforated  phosphor  bronze  band  off  the  sprocket  wheel  so 
that  it  will  be  possible  to  turn  the  sprocket  wheel  until  the 
center  type  wheel  has  made  at  least  one  complete  revolution  in 
each  direction,  during  which  time  the  sprocket  wheel  will  have 
made  seventy-two  revolutions.  In  passing  from  one  foot  mark 
to  another  turn  the  sprocket  wheel  slowly.  Before  taking  the 
metal  band  off  the  sprocket  wheel  put  a  mark  with  a  soft  pencil 
on  both  band  and  sprocket  wheel  flange  so  that  the  band  may  be 
put  back  quickly  into  the  same  position.  Raise  the  counter- 
weight (51)  about  6  inches  and  put  a  pin  through  the  same  per- 
forated band  at  the  base  of  the  instrument  to  support  the  weight 
and  use  a  piece  of  cord  tied  to  the  top  of  the  register  to  loop 
up  the  tape  so  that  it  will  not  be  damaged  during  the  operation. 

The  small  screw  in  the  center  of  the  shaft  that  supports  the 
sprocket  and  type  wheels  should  be  removed  and  in  its  place 
should  be  screwed  the  small  pump  furnished  for  that  purpose, 
filled  with  oil.  The  oil  should  be  forced  in  as  quickly  as  pos- 
sible and  the  operation  repeated  two  or  three  times  until  the  oil 
runs  out  between  the  type  wheels. 


WATER    STAGE    REGISTERS  101 

Gurley  Graphic  Water  Stage  Registers 

Normal  Vertical  Range,  0  to  10  feet 
Time  Scale,  7  days,  4  days,  or  1  day 

Patented  Aug.  4,  1914. 

Fig.   50  on  page   103   illustrates   an   improved  Graphic 
Register  having  several  unique  and  valuable  feartiir£s%    .It  is 
of  simple  construction,  with  few  parts;  is  designed!  for  easy, 
operation,  and  adapted  for  a  wide  range    oF'bou^ti^.,^  It9^ 
construction  is  such  that  no  lost    motion    will/ "develop   from' 
continuous  service  and  it  can  be  operated  with  minimum  care 
and  expense. 
The  following  vertical  scales  can  be  furnished: 

0  to  1  foot,  0  to  5  feet,          0  to  15  feet, 

0  to  r/2  feet,  0  to  6  feet,          0  to  20  feet, 

0  to  2  feet,  0  to  8  feet,          0  to  V/2  meters, 

0  to  3  feet,  0  to  10  feet,        0  to  3  meters. 

0  to  4  feet, 0  to  12  feet, 

A  time  scale  of^Tday)  4  days,  or  7  days  can  be  furnished. 
As  the  record  of  stage  is  made  around  the  cylinder,  there  is  no 
limit  to  the  number  of  revolutions  possible  and,  hence,  to  the 
range  of  stage.  Therefore,  it  is  advisable  to  use  as  low  a 
range  as  possible  and  hence  a  more  accurate  reading  of  the 
water  stage.  If  occasionally  the  water  'stage  is  above  the 
range  of  the  register,  no  trouble  will  be  experienced  in  read- 
ing the  water  level. 

ADVANTAGES  OF  GURLEY  GRAPHIC  REGISTERS 

Constancy  of  performance.  These  registers  have  been 
brought  to  their  present  high  state  of  excellence  through  years 
of  experiment.  They  have  been  developed  to  meet  actual  field 
conditions  and  are  performing  with  satisfaction  under  a  great 
variety  of  physical  conditions  in  all  parts  of  the  world.  Once 
properly  installed  they  require  a  minimum  of  attention. 

Low  cost.  From  the  standpoint  of  maintenance  and 
operation  Gurley  Water  Stage  Registers  represent  the  smallest 
possible  permanent  investment.  First  cost  is  also^  reduced  to 
a  minimum  in  these  registers. 

Mechanical  excellence.  Every  part  is  made  of  properly 
selected  material  finely  finished  to  insure  accuracy  of  opera- 


102         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

tion.  The  superior  mechanical  execution  is  accomplished  by 
expert  workmen  in  a  factory  that  has  been  producing  precision 
instruments  for  the  past  seventy-three  years. 

Reliability  of  the  time  parts.  Only  properly  adapted 
clocks  are  used  in  Gurley  registers.  They  have  properly 
proportioned  springs  and  the  escapement  has  jewelled  bearings 
to  insure,  uniformity  of  rate.  The  time  screws  that  drive  the 
;  pencil  carriage  are  machined  with  great  accuracy,  thus  insuring 
•a uniform. movement  of  the  pencil  over  the  record  sheet. 
s  ^  ^  •  Unlimited  range  of  stage.  The  record  of  stage  is  made 
around  the  cylinder, — the  time  record  along  its  axis — and  the 
cylinder  revolves  as  the  stage  changes.  There  is  no  limit  to 
the  number  of  revolutions  possible  and  hence  to  the  range  of 
stage,  while  at  the  same  time  the  movement  of  the  pencil  is 
always  in  one  direction,  which  assists  materially  in  interpret- 
ing the  record. 

Portability.  The  light  weight  of  these  registers  renders 
them  easily  portable  and  hence  adapts  them  to  those  special 
hydraulic  investigations  during  which  it  is  necessary  to  make 
frequent  changes  in  the  position  of  the  register. 

Type  of  record.  The  hydrograph  or  curve  recording  the 
stage  and  time  is  continuous  over  seven  days  and  presents 
graphically  all  of  the  fluctuations  of  stage  and  their  time  rela- 
tions. These  are  shown  at  a  glance  by  the  curve,  which  is  a 
picture  record  of  conditions.  This  type  of  record  has  many 
advantages  and  is  especially  useful  in  many  situations. 

Simplicity  of  the  record.  The  graphic  record  is  easily 
interpreted  and  where  desired,  may  be  quickly  reduced  to 
statistical  form. 

Precision  and  convenience  in  changing  record  sheets. 
The  record  sheets  are  cut  to  fit  the  cylinder  closely  and  the 
pencil  carriage  is  adjustable,  thus  insuring  an  accurate  setting 
of  the  time.  The  cylinder  is  securely  locked  in  place  while 
changing  the  record  sheet. 

The  permanence  of  the  setting  of  the  register  to  the  bench 
mark.  The  slot  which  extends  through  the  entire  length  of 
the  recording  cylinder  and  the  two  guards  that  prevent  the 
perforated  phosphor  bronze  band  from  accidentally  slipping 
over  the  spines  on  the  sprocket  wheel  when  the  record  is  being 
taken  off,  prevent  any  change  or  mistake  being  made  by  the 


WATER    STAGE    REGISTERS 


103 


FIG.  50. —  No.  633  Gurley  Graphic  Water  Stage  Register,  with 

Spring-driven  Clock.   , 

Normal  Range,  0  to  10  feet.     Time  Scale,  7  days. 

For  modifications  in  vertical  range  and  time  scale,  see  page  101. 

(See  Record  Sheet  illustrated  on  page  116.) 


104        W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

observer  while  handling  the  register,  after  it  has  been  properly 
installed  by  the  engineer  in  charge. 

Changing  the  range  of  the  register.  Simplicity  in  chang- 
ing two  gears  to  alter  the  range  of  the  register. 

Size  of  sheets.  The  record  sheets  are  adapted  to  con- 
venient filing  in  standard  filing  equipment. 

CONSTRUCTION  OF  NO.  633  GRAPHIC  REGISTER 

(The  part  numbers  refer  to  Fig.  51.) 

The  base  (1)  supports  the  mechanism  of  the  register. 
An  extra  heavy  eight-day  clock  (2)  is  geared  to  two  time 
screws  (3),  which  are  supported  at  each  end  as  shown.  The 
clock  has  two  large  driving  springs  and  has  jewelled  bearings 
on  the  escapement  shaft.  Mounted  on  the  two  screws  is  the 
pencil  carriage  (4)  which  moves  forward  without  lost  motion,  in 
accord  with  the  turning  of  the  clock  shaft,  and  which  can  be 
lifted  up  from  one  position  on  the  screws  and  placed  in 
another,  if  desired.  The  pencil  (11)  is  held  in  the  pencil 
holder  (5),  which  is  free  to  move  vertically  in  a  cylinder  (6) 
projecting  from  the  upper  side  of  the  base  of  the  carriage 
(4).  The  pencil  holder  (5)  is  set  and  the  pencil  clamped 
with  a  screw  (25),  so  that  the  weight  of  the  pencil  and  holder 
presses  down  against  the  paper. 

The  record  cylinder  (8),  on  which  the  paper  is  placed, 
is  supported  at  each  end  as  shown.  The  sprocket  wheel  (7) 
is  attached  to  the  sprocket  wheel  shaft  (26),  and  revolves  in  an 
eccentric  bushing  (24).  The  gear  (20)  is  clamped  to  the 
sprocket  wheel  shaft  by  the  nut  (15).  The  gear  (21)  is 
clamped  to  the  cylinder  (8)  by  three  small  screws.  Two 
guards  (9  and  10)  prevent  the  band  from  slipping  over  the 
spines  on  the  sprocket  wheel.  The  bolt  (13)  is  used  to  lock 
the  cylinder,  while  changing  the  record  sheet.  Extending 
across  the  face  of  the  record  cylinder  (8)  is  a  slot  (12),  which 
indicates  the  point  of  zero  gage  height  on  the  record  cylinder. 
Idler  pulley  (17)  is  used  to  spread  the  metal  band  so  that  the 
counterweight  will  pass  the  float.  There  is  a  gear  (19)  on  the 
center  clock  shaft.  The  capstan  head  screw  (18)  is  used  for 
clamping  the  gear  (19)  to  the  clock  shaft.  Three  nuts  (22) 
serve  to  hold  the  cover  on  the  register.  Clamp  screw  (23)  is 
to  clamp  the  bushing  in  the  base  (1). 


WATER    STAGE    REGISTERS 


105 


In  the  standard  register  of  this  type  the  pencil  travels 
along  the  cylinder  in  seven  days  time  (one  inch  for  each  day). 
It  is  possible,  however,  to  substitute  other  screws  (3)  of  such 
a  lead  that  the  pencil  will  move  across  the  cylinder  in  four 
days  (two  inches  jor  each-5 day),  or  screws  that  will  move  the 
pencil  across  the  cylinder  in  one  day  (eight  inches  per  day). 
Such  an  arrangement  would  be  very  desirable  in  situations 
where  there  are  sudden  fluctuations  in  stage. 

A  float  10  inches  in  diameter  and  3%  inches  thick  is  used. 
The  whole  instrument  is  enclosed  in  a  sheet  metal  cover  (14), 
15  inches  long,  8T4  inches  wide  and  11/4  inches  high,  which 
makes  it  waterproof  and  dustproof. 

Weight-driven  Graphic  Register  No.  636,  shown  in  Fig.  52, 
is  similar  to  Register  No.  633,  with  the  exception  of  the  clock, 


FIG.  51. —  No.  633  Gurley  Graphic  Register. 


106 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


FIG.  52. —  No.  636  Gurley  Graphic  Water  Stage  Register,  with 

Weight-driven  Clock. 

Normal  Range,  0  to  10  feet.     Time  Scale,  7  days. 

For  modifications  m  vertical  range  and  time  scale,  see  page  101. 

(See  Record  Sheet  illustrated  on  page  116.) 

which  is  weight-driven,  the  weights  falling  at  the  rate  of  10 
inches  per  day.  If  this  register  is  set  high  enough  above  the 
water,  the  pencil  can  be  made  to  travel  across  the  paper  in 
two  weeks,  or  at  the  rate  of  %  inch  per  day. 


WATER     STAGE    REGISTERS          107 

INSTALLATION  AND  OPERATION  OF  GURLEY  GRAPHIC  REGISTERS 
NOS.  633  AND  636 

A  large  element  in  "the  satisfactory  operation  of  an 
automatic  register  is  proper  installation.  The  results  from 
the  best  register  will  be  impaired  by  improper  installation, 
whereas  a  register  properly  installed  will  give  a  record  the 
accuracy  of  which  depends  solely  on  the  adequacy  of  the  instru- 
ment. The  value  of  approximate  results  is  not  commensurate 
with  the  expense  of  an  automatic  register ;  therefore,  the  method 
of  installation  should  be  so  thorough  as  to  insure  accuracy. 

In  installing  an  automatic  register,  it  is  necessary  to  pro- 
vide a  well  for  the  float,  connected  with  the  water  to  be 
measured  by  an  intake  pipe.  If  necessary,  a  valve  should  be 
used  in  the  well  on  the  intake  pipe,  so  that  the  water  can  be 
throttled  to  prevent  any  surge  appearing  on  the  record  sheet. 

To  place  the  register  permanently.  The  register  is  usually 
placed  on  a  table  having  holes  cut  for  the  phosphor  bronze 
band.  Place  the  register  in  its  proper  position  and  fasten  it 
to  the  table  by  the  quarter-inch  bolts  that  are  furnished. 
Attach  the  metal  band  to  the  float;  lower  the  float  to  the  surface 
of  the  water;  bring  the  metal  band  up  through  the  table  and 
over  the  sprocket  wheel ;  then  down  through  the  table  and  attach 
the  counterweight. 

To  place  the  pencil  carriage  on  the  screws.  The  pencil 
carriage  is  engraved,  "Toward  clock".  It  is  important  to 
place  the  carriage  on  the  screws  in  the  correct  position.  To 
do  this,  tip  the  carriage  so  that  one  side  will  fit  on  the  screw, 
then  swing  down  as  on  a  hinge  until  it  rests  on  the  other  screw. 

To  set  the  pencil  to  the  exact  height.  Insert  the  record 
sheet  in  the  M  inch  deep  slot  which  extends  through  the  entire 
length  of  the  recording  cylinder.  This  will  hold  the  paper 
securely  and  always  bring  the  sheets  in  the  same  position  on 
the  cylinder.  Loosen  nut  (15).  The  pencil  point  being  the 
index,  hold  the  sprocket  wheel  so  it  cannot  move.  Turning 
the  recording  cylinder  until  the  pencil  indicates  on  the  paper 
the  correct  height  of  the  water,  clamp  the  gear  (20)  to  the 
sprocket  wheel  (7)  with  the  nut  (15). 

To  set  the  pencil  to  the  exact  time,  loosen  the  capstan  head 
screw  (18),  revolve  the  screws  (3)  by  turning  gear  (19)  with 


108         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

an  adjusting  pin,  until  the  pencil  point  indicates  the  exact  time; 
hold  the  gear  (19)  with  an  adjusting  pin,  and  clamp  the  gear 
(19)  to  the  clock  shaft  with  the  screw  (18). 

To  change  the  record  sheet,  raise  the  float  by  turning  the 
record  cylinder  (8)  and  lock  it  by  the  bolt  (13),  thus  bringing 
the  slot  (12)  in  the  most  convenient  position.  Cut  the  adhe- 
sive paper  on  the  margin  of  the  record  sheet.  With  finger  on 
the  inside  of  the  cylinder  (8),  push  out  the  ends  of  the  record 
sheet,  which  can  readily  be  taken  off  from  the  outside  of  the 
cylinder.  Insert  the  corner  of  the  new  sheet  that  indicates  the 


FIG.  53. —  Showing  method  of  inserting  ends  of  the 
Record  Sheet  in  the  Slot  in  the  Cylinder. 

highest  gage  height;  gradually  press  it  into  the  slot  until  the 
upper  end  of  the  sheet  is  in  the  slot;  bring  the  paper  around  the 
cylinder  and  insert  the  corner  of  the,  sheet  marked  0,  pressing 
it  in  without  kinking  the  paper  until  that  end  is  in  slot  (12). 
(See  Fig.  53).  Stick  a  small  piece  of  adhesive  paper  on  the 
margin  and  over  the  slot.  When  folding  the  edge  of  the 
record  sheets,  be  careful  to  keep  the  folded  edge  straight  or 
trouble  will  be  experienced  in  inserting  the  record  sheet  in  the 
slot  in  the  cylinder. 

Care  of  the  record  sheets.  It  will  facilitate  putting  record 
sheets  on  the  cylinder  if  after  folding  the  edge,  about  twelve 
record  sheets  are  put  in  a  2-inch  paper  tube  with  rulings 
toward  the  outside.  Roll  and  put  one  sheet  in  at  a  time,  so 
when  one  is  to  be  put  on  the  register,  it  will  not  be  necessary 
to  take  all  of  the  sheets  out  of  the  tube.  Keep  the  sheets  in  a 


WATER    STAGE    REGISTERS  109 

dry  place,  so  that  the  paper  will  be  hard  while  inserting  the 
record  sheet  in  the  cylinder.  If  it  is  desirable  to  keep  the 
record  sheets  in  the  gage  house,  the  paper  tube  with  the  record 
sheets  should  be  kept  in  a  'two-quart  fruit  jar,  and  when  taking 
record  sheets  out,  open  and  elose  the  jar  as  quickly  as  possible. 
If  the  atmosphere  is  damp  when  filling  the  jar  with  record 
sheets,  place  the  jar  with  the  sheets  in  a  hot  place  and  when 
heated  thoroughly,  put  a  rubber  ring  on  the  jar  and  screw  on 
the  cover. 

To  oil  the  register.  The  clock  will  run  two  years  with  one 
oiling;  however,  if  it  stands  idle  for  one  month,  it  will  be 
necesssary  to  take  off  the  hands  and  face  and  oil  it  with  the 
best  clock  oil.  The  bearings  of  the  screws  and  of  the  cylinder 
should  be  oiled  with  the  above  mentioned  oil  about  four  times 
a  year.  A  very  small  amount  of  oil  should  be  used  on  the 
screws  every  month.  A  fine  wire  should  be  used  in  applying 
the  oil. 


110         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

Gurley  Graphic  Water  Stage  Registers 

Normal  Vertical  Range,  0  to  1  foot  —  Natural  Scale. 
Time  Scale,  7  Days,  4  Days,  or  1  Day. 

Patented  August  4,  1914. 

This  register  may  be  used  as  a  natural  scale  graphic  register 
of  great  accuracy  for  a  normal  range  of  one  foot.  Multiples 
thereof  are  recorded  as  complete  revolutions  of  the  cylinder. 

The  float  furnished  with  the  register  is  10  inches  in  diameter. 
The  power  of  the  weight  of  a  column  of  water  10  inches  in 
diameter  and  1/100  of  a  foot  high  is  5.47  ounces.  Thus  this 
float  gives  great  lifting  power  and  corresponding  accuracy. 

The  natural  scale  register  is  designed  to  meet  those  re- 
quirements which  demand  a  full  size  record  of  stage.  As 
usually  constructed  the  time  scale  is  1  inch  per  day,  but  it  is 
possible  to  arrange  special  screws  to  other  scales.  This  register 
is  especially  adapted  to  the  measurement  of  the  flow  of  any 
liquid  over  weirs.  It  will  give  the  height  of  liquid  on  the 
weir  with  great  precision.  For  this  purpose  it  is  easily 
applied  to 

(1)  Sewage  disposal  works, 

(2)  Sanitary  sewers, 

(3)  Irrigation  works, 

(4)  Venturi  flumes. 

It  is  equally  well  adapted  to  use 

(5)  In  stream  gaging, 

(6)  On  power  canals, 

(7)  On  irrigation  canals, 

(8)  On  navigation  canals, 

(9)  On  drainage  canals, 

(10)  In  reservoirs  of  all  kinds, 

(11)  In  measuring  flow  from  pumps,  wells,  etc. 

(12)  As  a  portable  gage  for    use    in    special    studies 

and  investigations. 

Its  construction  is  such  that  no  lost  motion  will  develop 
from  continuous  service  and  it  can  be  operated  with  minimum 
care  and  expense.  This  instrument  is  a  perfect  weir  gage  and 


WATER    STAGE    REGISTERS 


111 


FIG.  54. —  No.  634  Gurley  Graphic  Water  Stage  Register. 

Normal  Range,  0  to  1  foot  —  Natural  Scale.    Time  Scale,  7  days. 

(See  Record  Sheet  illustrated  on  page  117.) 

If  this  register  is  equipped  with  a  sprocket  wheel  2  feet  in  circum- 
ference, instead  of  1  foot,  as  on  Register  No.  634,  the  range  of  the  instru- 
ment is  from  0  to  2  feet,  and  it  is  known  as  Register  No.  634-A. 


112         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

has  no  equal  in  simplicity  of  construction,  accuracy,  ease  of 
operation,  and  durability. 

These  Gurley  registers  are  being  used  extensively  by 
different  Departments  of  the  United  States  Government;  also 
by  many  municipalities  in  connection  with  their  sewer  systems 
and  sewage  disposal  plants. 

ADVANTAGES  OF  GURLEY  GRAPHIC  REGISTERS 

The  advantages  of  Registers  Nos.  634  and  634-A  are  the 
same  as  those  given  under  Registers  Nos.  633  and  636,  on 
pages  101,  102  and  104. 

CONSTRUCTION  OF  NO.  634  GRAPHIC  REGISTER 

(The  part  numbers  refer  to  Fig.  55) 

The  base  (1)  supports  the  mechanism  of  the  register.  An 
extra  heavy  eight-day  clock  (2)  is  geared  to  two  time  screws 
(3)  supported  at  each  end,  as  shown.  The  clock  has  two  large 
driving  springs  and  has  jewelled  bearings  on  the  escapement 
shaft.  Mounted  on  the  two  screws  is  the  pencil  carriage  (6) 
which  moves  forward  without  lost  motion,  in  accord  with  the 
turning  of  the  clock  shaft,  and  which  can  be  lifted  up  from  one 
position  on  the  screws  and  placed  in  another,  if  desired.  The 
pencil  (11)  is  held  in  a  pencil  holder  (5)  which  is  free  to  move 
vertically  in  a  cylinder  projecting  from  the  upper  side  of  the 
base  of  the  carriage  (4).  The  pencil  holder  (5)  is  set  and 
clamped  with  a  screw,  so  that  the  weight  of  the  pencil  and  the 
holder  presses  down  against  the  paper.  The  recording  cylinder 
(8),  on  which  the  paper  is  placed,  is  supported  at  each  end,  as 
shown.  The  sprocket  wheel  (7)  is  movable  on  the  cylinder 
axis  and  is  clamped  to  the  cylinder  (8)  by  the  nut  (15).  Two 
guards  (9  and  10)  prevent  the  band  from  slipping  over  the 
spines  on  the  sprocket  wheel,  and  bolt  (13)  is  used  to  lock  the 
cylinder,  while  changing  the  record  sheet.  Extending  across 
the  face  of  the  recording  cylinder  (8)  is  a  slot  (12),  which 
indicates  the  point  of  zero  gage  height  on  the  record  cylinder. 
In  the  standard  register  of  this  type  the  pencil  travels 
along  the  cylinder  in  seven  days  time.  It  is  possible,  how- 
ever, to  substitute  other  screws  (3)  of  such  a  lead  that  the 
pencil  will  move  across  the  cylinder  in  either  four  days,  or 


WATER    STAGE    REGISTERS 


113 


twenty-four  hours.  Such  an  arrangement  would  be  very 
desirable  in  situations  where  there  are  sudden  fluctuations  in 
stage. 


FIG.  55. —  No.  634  Gurley  Graphic  Register. 

Idler  pulleys  (17)  are  to  be  used  when  it  is  necessary  to 
allow  the  counterweight  to  pass  the  float.  On  the  center  clock 
shaft  is  a  gear  (19),  which  is  clamped  on  the  shaft  by  capstan 
head  screw  (18). 

A  float  10  inches  in  diameter  and  3T/2  inches  thick,  is  used. 
The  whole  instrument  is  enclosed  in  a  sheet  metal  cover  (14), 
15 ?4  inches  long,  7/^  inches  wide,  and  9  inches  high,  which 
makes  it  water-proof  and  dust-proof.  The  extension  (16)  is 
for  locking  the  cover  on  the  register. 

INSTALLATION   AND   OPERATION   OF   GURLEY  GRAPHIC   REGISTERS 
NOS.  634  AND  634-A 

A  large  element  in  the  satisfactory  operation  of  an  auto- 
matic register  is  proper  installation.  The  results  from  the 
best  register  will  be  impaired  by  improper  installation,  whereas 
a  register  properly  installed  will  give  a  record  the  accuracy  of 


114         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

which  depends  solely  on  the  adequacy  of  the  instrument.  The 
value  of  approximate  results  is  not  commensurate  with  the  ex- 
pense of  an  automatic  register;  therefore,  the  method  of  in- 
stallation should  be  so  thorough  as  to  insure  accuracy. 

In  installing  an  automatic  register,  it  is  necessary  to  pro- 
vide a  well  for  the  float,  connected  with  the  water  to  be 
measured  by  an  intake  pipe.  If  necessary,  a  valve  should  be 
used  in  the  well  on  the  intake  pipe,  so  that  the  water  can  be 
throttled  to  prevent  any  surge  appearing  on  the  record  sheet. 

To  place  the  register  permanently.  The  register  is  usually 
placed  on  a  table  having  holes  cut  out  for  the  phosphor  bronze 
band.  Place  the  register  in  its  proper  position  and  fasten  it 
to  the  table  by  the  quarter- inch  bolts  that  are  furnished.  Attach 
the  metal  band  to  the  float;  lower  the  float  to  the  surface 
of  the  water;  bring  the  metal  band  up  through  the  table  and 
over  the  sprocket  wheel;  then  down  through  the  table  and 
attach  the  counterweight.  If  the  register  is  set  high  enough, 
it  is  unnecessary  to  pass  the  metal  band  over  the  pulleys  (17). 

To  place  the  pencil  carriage  on  the  screws.  The  pencil 
carriage  is  engraved,  "Toward  clock."  It  is  important  to 
place  the  carriage  on  the  screws  in  the  correct  position.  To 
do  this,  tip  the  carriage  so  that  one  side  will  fit  on  the  screw, 
then  swing  down  as  on  a  hinge  until  it  rests  on  the  other  screw. 

To  set  the  pencil  to  the  exact  height.  Insert  the  record 
sheet  in  the  24  inch  deep  slot  which  extends  through  the  entire 
length  of  the  recording  cylinder.  This  will  hold  the  paper 
securely  and  always  bring  the  sheets  in  the  same  position  on 
the  cylinder.  Loosen  the  nut  (15).  The  pencil  point  being 
the  index,  hold  the  sprocket  wheel  so  it  cannot  move;  turn 
the  recording  cylinder  until  the  pencil  indicates  on  the  paper 
the  correct  height  of  the  water;  and  clamp  the  sprocket  wheel 
(7)  to  the  cylinder  (8)  with  the  nut  (15). 

To  set  the  pencil  to  the  exact  time,  loosen  the  capstan  head 
screw  (18),  revolve  the  screws  (3)  by  turning  gear  (19)  with 
an  adjusting  pin  until  the  pencil  point  indicates  the  exact  time; 
hold  the  gear  (19)  with  an  adjusting  pin,  and  clamp  the  gear 
(19)  to  the  clock  shaft  with  the  screw  (18). 

To  change  the  record  sheet,  raise  the  float  by  turning  the 
record  cylinder  (8)  and  lock  it  by  the  bolt  (13),  thus  bringing 


WATER    STAGE    REGISTERS  115 

the  slot  (12)  in  the  most  convenient  position.  Cut  the  adhesive 
paper  on  the  margin  of  the  record  sheet.  With  finger  on  the 
inside- of  the  cylinder  (8),  push  out  the  ends  of  the  record 
sheet,  which  can  readily  be  taken  off  from  the  outside  of  the 
cylinder.  Insert* the  corner  of  the  new  sheet  marked  1.00; 
gradually  press  it  into  the  slot  until  the  upper  end  of  the  sheet 
is  in  the  slot;  bring  the  paper  around  the  cylinder  and  insert 
the  corner  of  the  sheet  marked  0,  pressing  it  in  without  kinking 
the  paper  until  the  end  is  in  slot  (12) .  (See  Fig.  53,  page  108) . 
Stick  a  small  piece  of  adhesive  paper  on  the  margin  and  over 
the  slot.  When  folding  the  edge  of  the  record  sheets,  be  careful 
to  keep  the  folded  edge  straight,  or  trouble  will  be  experienced 
in  inserting  the  record  sheet  in  the  slot  in  the  cylinder. 

Care  of  the  record  sheets.  It  will  facilitate  putting  record 
sheets  on  the  cylinder  if  after  folding  the  edges,  about  twelve 
record  sheets  are  put  in  a  2-inch  paper  tube  with  rulings 
toward  the  outside.  Roll  and  put  one  sheet  in  at  a  time,  so 
when  one  is  to  be  put  on  the  register,  it  will  not  be  necessary 
to  take  all  of  the  sheets  out  of  the  tube.  Keep  the  sheets  in  a 
dry  place,  so  that  the  paper  will  be  hard  while  inserting  the 
record  sheet  in  the  cylinder.  If  it  is  desirable  to  keep  the 
record  sheets  in  the  gage  house,  the  paper  tube  with  the  record 
sheets  should  be  kept  in  a  two-quart  fruit  jar,  and  when  taking 
record  sheets  out,  open  and  close  the  jar  as  quickly  as  possible. 
If  the  atmosphere  is  damp  when  filling  the  jar  with  record 
sheets,  place  the  jar  with  the  sheets  in  a  hot  place  and  when 
heated  thoroughly,  put  a  rubber  ring  on  the  jar  and  screw  on 
the  cover. 

To  oil  the  register.  The  clock  will  run  two  years  with  one 
oiling;  however,  if  it  stands  idle  for  one  month,  it  will  be 
necessary  to  take  off  the  hands  and  face  and  oil  it  with  the  best 
clock  oil.  The  bearings  of  the  screws  and  of  the  cylinder 
should  be  oiled  with  the  above  mentioned  oil  about  four  times 
a  year.  A  very  small  amount  of  oil  should  be  used  on  the 
screws  every  month.  A  fine  wire  should  be  used  in  applying 
the  oil. 


116         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


GURLEY    SEVEN    DAY  GRAPHIC    REGISTER 


OUt'icl  Offlc*  . 


Stiff  i»t«  h.:f ht . 


FIG.  56. —  Record  Sheet  for  No.  633  or  No.  636  Graphic  Register. 

Normal  range,  0  to  10  feet.    Time  scale,  7  days. 

See  pages  103  and  106. 


WATER    STAGE    REGISTERS  117 


FIG.  57. —  Record  Sheet  for  No.  634  Graphic  Register. 

Normal  range,  0  to  1  foot  —  Natural  Scale.     Time  Scale,  7  days. 

See  page  111. 


118 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


INSTALLATION  AND  SHELTER  OF  WATER 
STAGE  REGISTERS 

When  an  automatic  register  is  used  continuously  it  is 
necessary  to  provide  (1)  a  well  for  the  float  and  an  intake 
pipe  to  connect  the  well  with  the  river,  (2)  a  house  to  shelter 
the  register,  and  (3)  staff  or  hook  gages  referred  to  permanent 
bench  marks  for  use  in  checking  the  record  and  maintaining 
the  datum.  (See  Figs.  40  and  41).  For  temporary  use  as  in 
special  studies,  a  portable  shelter,  Figure  58,  may  be  used. 


FIG.  58. —  Portable  Shelter  installed  by  U.  S.  Geological  Survey  on  Kinder- 
hook  Creek  at  Rossman,  N.  Y.         The  insert  shows  the  outfit, 
including  a  Gurley  Graphic  Register,  packed  ready  to  carry. 

Proper  installation  is  so  large  an  element  in  the  satisfac- 
tory operation  of  an  automatic  water  stage  register  that  much 
care  should  be  taken  when  installing  the  equipment.  Results 
from  the  best  of  registers  will  be  impaired  by  improper  instal- 
lation, whereas  a  register  properly  installed  will  give  a  record 
whose  accuracy  depends  solely  on  the  refinement  of  the  instru- 
ment. Much  care  in  installation  is,  therefore,  essential;  and^ 


WATER    STAGE    REGISTERS  119 

if  the  register  is  to  record  stream  heights  during  Winter  months 
and  during  flood  stages,  the  installation  must  be  protected  from 
cold  and  from  floating  ice,  logs,  debris,  etc. 

In  the  ideal  structure,  illustrated  in  Fig.  25,  the  well 
and  the  house  should  be  located  far  enough  back  from  the  river 
to  be  out  of  danger  from  floating  ice  or  drift,  and  to  provide 
sufficient  protection  for  the  well  and  pipes  to  prevent  freezing. 
A  permanent  ladder  should  extend  to  the  bottom  of  the  well,  so 
that  the  float  and  intake  pipe  can  be  readily  inspected.  If  the 
installation  is  to  be  maintained  for  a  long  period  the  well  should 
be  lined  with  concrete,  otherwise  a  heavy  plank  lining  may  be 
used.  The  intake  pipe  should  be  placed  well  below  the  lowest 
stage  of  the  river  and  provided  with  a  screen  for  keeping  out 
fish  and  foreign  material.  It  should  also  be  provided  with  a 
gate  valve  where  it  enters  the  well,  so  that  the  flow  can  be  re- 
duced if  necessary,  to  eliminate  wave  action,  or  entirely  shut 
off  for  purposes  of  inspection  or  for  repairs. 

Two  non-recording  gages,  referred  to  permanent  bench 
marks,  should  be  installed  with  each  automatic  register,  in  order 
to  check  the  readings  of  the  automatic  register  with  the  stage 
of  the  river.  One,  of  the  type  best  suited  to  the  locality,  should 
be  placed  in  the  river  and  the  other,  preferably  a  hook  gage, 
should  be  located  in  the  float  well  to  aid  in  setting  and  checking 
the  recording  register,  and,  by  comparison  with  the  river  gage, 
to  indicate  any  interruption  in  the  free  communication  with 
the  river.  The  river  gage  should  be  in  the  same  cross-section 
of  the  river,  as  the  intake  pipe,  care  being  taken  to  have  it  rest 
on  a  solid  foundation.  It  may,  however,  be  dispensed  with  by 
using  a  reference  point  so  located  that  the  elevation  of  the 
water  surface  can  be  readily  determined. 

The  well  is  essentially  a  stilling  box  for  the  float.  It  must 
be  large  enough  to  accommodate  the  float,  driving  and  counter 
weights,  and  the  hook  or  staff  gage,  from  extreme  low  to  ex- 
treme high  water,  and  to  permit  them  to  be  inspected  readily. 
Experience  shows  that  if  the  well  is  more  than  8  feet  deep 
these  conditions  are  met  best  by  a  well  2%  by  5  feet  in  cross- 
section.  For  wells  up  to  sixteen  feet  in  depth  this  cross-section 
will  give,  in  the  long  run,  greater  satisfaction  than  a  smaller 
one,  while  even  for  deeper  wells,  if  in  easily  excavated  material, 


120         W.  &  L.  E.  GURLEY,  TROY,  N.  Y; 

it  may  cost  no  more.  When  for  good  reason  high  priced  ma- 
terials of  construction  are  used,  the  reduction  of  the  dimensions 
of  the  cross-section  to  3  by  4  feet  may  be  advantageous,  es- 
pecially if  it  is  possible  to  provide  several  entrances  to  the 
well  between  high  and  low  water. 

The  materials  of  construction  suitable  for  lining  wells 
include  timber  (usually  treated  with  a  wood  preservative), 
brick,  vitrified  tile  pipe,  concrete,  plain  or  reinforced  in  mass, 
concrete  rings,  stone,  cast  iron  pipe,  riveted  steel  pipe,  and 
galvanized  wrought  iron  culvert  pipe. 

On  the  degree  of  certainty  with  which  the  useful  life  of 
the  station  may  be  predicted  will  depend  the  general  choice  of 
the  material  to  use  at  any  given  station,  longer  usefulness 
requiring  more  durable  material.  The  specific  choice  will 
depend  on  the  accessibility  of  the  station  and  on  the  availability 
of  labor  and  material. 

In  northern  latitudes  attention  must  be  given  to  the  possi- 
bility of  the  water  in  the  well  freezing,  with  the  consequent 
interruption  of  the  record,  but  in  a  well  properly  constructed 
and  placed  far  enough  back  from  the  river  there  should  be  no 
danger  from  frost,  even  in  temperature  as  low  as  30  degrees 
below  zero.  Several  methods  are  available,  the  choice 
among  them  being  made  on  the  basis  of  first  cost  versus 
cost  of  operation.  Where  the  first  method  is  used, — that  of 
higher  first  cost, — the  well  is  placed  far  enough  back  in  the 
bank  to  be  protected  against  cold.  To  obtain  this  protection 
the  well  should  be  built  so  that  the  water  surface  during  the 
Winter  season  is  at  least  two  feet  below  the  depth  of  maximum 
frost.  Guarding  against  the  possibility  of  freezing  allows  more 
freedom  in  the  choice  of  observers. 

Where  such  construction  does  not  seem  advisable 
an  oil  cover  may  be  applied,  using  a  depth  of  oil 
equal  to  the  maximum  thickness  of  ice,  plus  2  feet. 
A  device  for  reducing  the  quantity  of  oil  required  is 
shown  in  Fig.  59.  In  some  cases  the  device  of  building  a 
jacket  around  an  exposed  well  has  been  resorted  to.  Between 
the  well  and  the  jacket  a  space  of  2  feet  is  left,  which  is  filled 
with  manure,  leaves,  or  some  similar  material.  The  jacket 
is  carried  up  8  feet  above  the  water  surface. 


WATER    STAGE    REGISTERS  121 


FIG.  59. —  Device  for  reducing  quantity  of  oil  used 
as  a  cover  in  wells. 

If  near  a  suitable  electric  circuit,  an  electric  heater  can 
be  used  in  the  end  of  a  24  inch  galvanized  pipe,  the  heated  end 
resting  on  the  bottom  of  the  well  and  the  pipe  being  long 
enough  to  extend  through  the  floor  of  the  register  house.  The 
heater  should  be  used  only  in  extremely  cold  weather.  A 
rheostat  that  could  be  attached  to  the  under  side  of  a  float  and 
which  would  turn  on  the  current  when  the  water  was  34  degrees 
Fahrenheit  would  be  desirable  for  economy.  If  the  water  in 
the  well  is  over  heated,  everything  in  the  register  house  will  be 
covered  with  a  heavy  coating  of  frost  and  thus  interfere  with 
the  working  of  the  register. 

The  type  of  house  to  be  used  at  any  station  is  selected 
after  consideration  has  been  given  to  the  three  elements, — 
utility,  safety,  and  appearance.  If  a  station  is  to  be  operated 
all  year  round  the  house  must  be  large  enough  to  allow  the 
observer  to  go  inside  during  inclement  weather  and  to  pass  con- 
veniently around  the  register  table  while  inspecting  or  adjusting 
the  register.  Plenty  of  light  in  the  shelter  is  very  desirable  when 
setting  the  gage  height,  changing  the  record,  or  otherwise  ad- 
justing the  register.  For  a  permanent  field  installation  a  con- 
crete well  and  shelter,  which  will  also  afford  fire  protection, 
(Figs.  60  and  61),  are  recommended  as  a  matter  of  economy. 


122         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

Portable  wooden*  or  sheet  metal  houses**,  5  by  6  feet  in  plan, 
have  been  used  with  success  in  appropriate  locations.  The  cost  of 
such  shelters  is  small,  and  they  may  be  obtained  quickly  from 
stock  from  their  manufacturers.  In  arid  regions,  if  the 
station  is  to  be  operated  only  during  warm  weather  and  where 
rain  is  not  likely  to  interfere  with  the  inspection  and  adjustment 
of  the  register,  simpler  types  of  shelters  may  be  used. 

When  registers  are  to  be  installed  at  dams,  provision 
should  be  made  in  the  design  of  the  dam  for  a  well  of  ample 
size  and  a  shelter  to  form  part  of  the  structure.  The  same 
provision  should  be  made  when  designing  bridge  piers  or  bulk- 
heads to  be  built  in  streams  at  points  where  records  may  be 
desired. 

Each  shelter  should  be  provided  with  a  suitable  register 
table,  and  a  saving  of  time  will  result  from  keeping  perman- 
ently in  each  shelter  certain  tools  and  equipment.  For  the 
small  adjusting  levers,  screw  drivers,  oil  cans,  etc.,  required 
in  operating  the  automatic  register,  a  small  box  may  be  fast- 
ened to  the  wall  of  the  shelter.  A  couple  of  thin  battens  con- 
veniently placed  will  serve  as  a  paper  rack,  behind  which  may 
be  placed  stationery  or  wrapping  paper  that  may  be  required 
at  the  station.  A  broom  will  frequently  be  found  useful,  and 
a  tin  pail,  a  shovel,  an  ice  chisel,  a  stay  line  and  lead  meter 
weights  should  be  kept  at  the  shelter  when  current  meter  meas- 
urements are  made  nearby. 


CARE  AND  COMPUTATION  OF  RECORDS 

Records  from  Gurley  Printing  Water  Stage  Registers 
should  be  wound  on  a  tin  spool  furnished  for  that  purpose,  as 
soon  as  they  are  received  at  the  office.  A  No.  632  Tape  Reel 
(See  Fig.  46,  page  90)  will  be  of  material  assistance  in  this 
process,  especially  in  dividing  the  record  for  computation,  into 
days,  by  means  of  pencil  lines  drawn  across  the  paper  strip. 
One  months  record  may  be  rolled  on  one  spool,  and  the  spools 
may  be  filed  in  a  filing  cabinet  or  drawer.  All  information  per- 
taining to  the  gage  height  should  be  made  on  separate  sheets, 
which  are  then  properly  filed  away  for  reference.  The  printed 

*Miller  Manufacturing  Co.,  8000  Alabama  Ave.,  St.  Louis,  Mo. 
**Metal  Shelter  Co.,  Whitehall  Bldg.,  New  York  City. 


WATER    STAGE    REGISTERS  123 


<-• 


124 


W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 


FIG.  62. —  Galvanized  sheet  metal   Shelter  and  Well,   installed  by    U.    S. 
Engineer  Department  at  Pier  A,  the  Battery,  New  York  City.    Equipped 
with  a  No.  630  Gurley  Printing  Register — one  of  19  similar  instru- 
ments installed  along  the  Hudson  River  for  a  distance  of  150 
miles  between  New  York  City  and  Troy. 


FIG.  63. —  Metal   Shelter  with  door    open,    showing    the    Gurley    Printing 

Register  —  with  its  cover  removed  —  standing  on  a  wooden  table  ; 

also  the  weights  suspended  in  the  well. 


WATER    STAGE    REGISTERS 


125 


FIG.  64. — Wooden  Well  and  Shelter  housing    a    No.    G36    Gurley    Graphic 

Register  installed  by  the  U.  S.  Geological  Survey  on  the  Genesee 

River  at  Jones  Bridge  near  Mt.  Morris,  N.  Y.     The  river 

is  shown  under  flood  conditions  during  March,  1916, 

when  the  Register  obtained  a  complete 

record  of  the  flood. 


FIG.  65. — Water  Stage  Register  installation  by  U.  S.  Geological  Survey  on 

the  Santa  Maria  Creek  in  California,   showing  an  inexpensive 

wooden  shelter,  a  vertical  staff  gage,  and  an 

artificial  control. 


126 


W.  &  L.  E.  G  U  R  L  E  Y,  TROY,  N.  Y. 


FIG.  66. — Wooden  Well  and  Shelter  installed  by  the  U.  S.  Geological  Survey 

at  a  bridge  abutment  on  the  Susquehanna  River  near  Conklin,  N.  Y. 

Note  elevation  of  shelter  to  provide  for  flood  stage. 


FIG.  67. — Wooden  Well  and  Shelter  installed  by  the  U.  S.  Geological  Survey 

on  the  Brazos  River  at  Waco,  Texas.     Equipped  with  a  Gurley 

Graphic  Register.     Note  method  of  installation  against  bridge 

pier,  instead  of  at  usual  place  on  stream  bank. 


WATER    STAGE    REGISTERS  127 

DEPARTMENT  OF  THE  INTERIOR  FILE  No. 

UNITED  STATES  GEOLOGICAL  SURVEY 

WATER  RESOURCES  BRANCH  Washington 

Date 191___  Field 

INSPECTION  OF  AUTOMATIC  GAGE 


River,  at 


Was  gage  working  properly  when  you  reached  it? 

What  is  correct  time  by  your  watch? 

What  is  the  clock  time? 

What  is  the  time  by  the  pen  or  pencil? 

What  is  the  outside  or  river  gage  reading? 

What  is  the  inside  or  well  gage  reading? 

What  is  the  automatic  gage  reading? 

Have  you  marked  pen  or  pencil  time  on  the  chart  by  raising  the  float? 

Did  you  remove  old  sheet  and  put  on  new  one? At  what  time 

did  you  do  this? 

If  you  did  not  remove  sheet,  did  you  correct  setting  of  pen  or  pencil  and 

clock? 

Did  you  wind  clock? Regulate  it? 

Did  you  sharpen  pencil  or  fill  pen? 

Did  you  mark  pen  or  pencil  time  on  new  sheet  by  raising  float? 

Have  you  filled  blanks  on  old  sheet  according  to  instructions? 

Have  you  made  sure  that  pen  or  pencil  is  down,  sheet  placed  correctly,  set 

screw  on  drum  fastened,  and  gage  working  correctly  before  leaving 

station? 

Have  you  filled  all  blanks  on  this  sheet  according  to  instructions? 

Remarks  and  questions  :   _ 


Signed  by 

O  6  server. 


FIG.  68. — U.   S.  Geological   Survey  Form  for  Inspection  of 
Recording  Register  Stations. 


128         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

strip  should  be  dated  and  otherwise  marked  for  identification, 
and  the  computations  should  be  made  at  once.  The  computer  sits 
down  at  the  adding  machine  with  the  record  on  the  tape  reel 
and  with  a  rating  table  having  the  gage  heights  carried  out  to 
hundredths;  then  looks  up  the  gage  height  for  each  hour  and 
takes  out  the  corresponding  discharge  on  the  machine.  At  the 
end  of  the  day  the  twenty-four  discharges  are  totaled.  All  these 
additions  are  made  on  letter  size  paper,  one  sheet  holding  the 
computations  for  about  twelve  days,  each  column  of  figures 
being  headed  with  the  date.  A  sheet  of  carbon  paper  is  re- 
versed behind  the  paper  so  that  it  can  be  reproduced  by  blue 
printing  when  necessary.  By  this  method,  one  month's  record 
can  be  totaled  in  about  two  hours. 

The  pencil  records  from  graphic  type  registers  should  be 
inked  in  with  black  drawing  ink,  using  a  fine  pen.  The  inking 
may  be  done  on  the  back  of  the  sheet,  thus  preserving  the 
pencil  record  in  its  original  form,  by  placing  the  record  on  the 
glass  cover  of  a  shallow  frame  which  has  an  electric  lamp 
underneath. 

Notes  or  other  information  pertaining  to  the  gage  height 
should  be  entered  on  the  original  sheet,  as  should  also  the  name 
of  the  station,  the  date  of  the  end  of  the  record,  and  the  gage 
height  scale.  In  some  cases  it  may  be  advantageous  to  use  a 
rubber  stamp  for  this  data. 

For  use  with  the  graphic  type  registers  a  discharge 
scale  for  each  station  may  be  pasted  on  a  celluloid 
triangle.  A  steel  straight  edge  may  then  be  clamped  on  a 
drawing  board  over  the  record  in  such  a  position  that  the  tri- 
angle sliding  along  it  will  always  be  in  the  proper  position.* 
The  hourly  discharges  are  then  read  off  by  the  use  of  the  scale 
and  are  entered  on  an  appropriate  ruled  form. 

OTHER  APPLICATIONS  OF  GURLEY  CURRENT  METERS 
AND  WATER  STAGE  REGISTERS 

The  successful  use  of  Gurley  Current  Meters  and  Water 
Stage  Registers  in  connection  with  problems  of  river  discharge 
has  led  to  their  application  to  similar  problems  in  related  fields. 
Some  details  of  a  number  of  these  uses  are  given  below. 

*See  Engineering  News  for  August,  1914,  page  458  ;  also  for  June 
25,  1914,  page  1430. 


WATER    STAGE    REGISTERS  129 


FIG.  69. —  One  of  six  No.  634  Gurley  Graphic  Registers  installed  in 
specially  designed  manholes  in  the  joint  outlet  sewer  constructed  by  the 
New  Jersey  cities  and  towns  of  Newark,  Summit,  South  Orange,  West 
Orange,  Irvington,  Milburn  and  Vailsburgh.  South  Orange  Township 
later  acquired  rights  to  discharge  500,000  gallons  of  sewage  daily  into 
the  sewers  of  Milburn.  It  being  impracticable  to  locate  weirs  in  the 
sewers,  owing  to  the  large  volume  of  solids,  six  Gurley  Registers  were 
installed  to  keep  accurate  record  of  the  flow.  A  man  visits  the  instru- 
ments once  a  week  to  wind  the  clock  and  change  the  charts.  The 
record  is  kept  in  natural  scale  and  the  total  flow  is  quickly  computed. 

MEASUREMENT  OF  SEWAGE 

The  growth  of  population  of  cities  and  the  increased  at- 
tention that  has  been  given  to  municipal  sanitation  has  empha- 
sized the  importance  of  the  design  and  construction  of  sanitary 
sewers  and  of  works  for  the  disposal  of  sewage. 

As  usually  designed  the  sewers  are  for  practical  reasons 
of  ample  cross -section  to  afford  a  wide  margin  of  capacity. 
With  raw  sewage  being  discharged  into  natural  waterways 
little  attention  has  been  paid  heretofore  to  the  quantity  dis- 
charged, and  few  cities  have  any  record  of  the  actual  discharge 
of  their  sewers.  In  many  cases  the  low  dilution  of  the  sewage 
by  the  natural  flow  of  the  stream  into  which  it  has  been  dis- 
charged, especially  at  times  of  low  flow,  has  been  the  cause  of 


130         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

many  nuisances.  Several  states  have  passed  laws  governing 
the  discharge  of  sewage  into  intra-state  waters  and  investi- 
gations upon  which  to  base  a  Federal  law,  covering  interstate 
streams,  are  now  under  way.  All  such  investigations  require 
a  knowledge  of  stream  flow.  In  fact,  the  question  of  whether 
the  sewage  from  a  proposed  or  existing  sewer  system  may  be 
discharged  into  a  given  stream  may  be  almost  entirely  decided 
upon  the  basis  of  the  quantity  of  sewage  and  the  minimum  flow 
of  the  stream,  both  of  which  quantities  it  is  possible  to  determine 
completely  by  the  use  of  Gurley  current  meters  and  automatic 
water  stage  registers. 

The  flow  of  all  streams  into  which  sewage  is  discharged 
should  be  a  matter  of  record  in  every  city  that  disposes  of  its 
sewage  in  this  way.  Such  information  may  be  obtained  readily 
by  means  of  the  current  meter  method  of  stream  gaging,  ex- 
plained on  pages  48  to  62. 

It  is  also  possible  to  apply  current  meter  methods  to  the 
measurement  of  the  flow  in  the  sewers  themselves.  In  applying 
these  methods,  it  will  be  possible  to  find  or  to  construct  in  the 
sewer  barrel  a  permanent  control  section  to  be  rated.  Because 
of  the  relatively  large  diurnal  fluctuations  of  depth  over  the 
control  to  be  expected  from  the  character  of  sewage  discharge, 
it  is  necessary  to  use  automatic  registers.  For  this  purpose 
Gurley  Graphic  Register  No.  634,  with  a  normal  range  of  one 
foot,  described  on  pages  110  to  115,  is  most  suitable.  The  float 
chamber  should  be  designed  as  a  part  of  the  sewer  itself  and 
built  at  the  same  time  the  sewer  is.  In  the  case  of  existing  sewers 
on  which  it  is  desired  to  keep  records  of  flow,  a  well  for  the  float 
may  be  built  alongside  the  sewer  at  the  proper  point  in  its 
length.  Gagings  of  this  character  have  been  carried  on  suc- 
cessfully in  the  city  of  Atlanta,  Ga.*  and  the  sewer  departments 
of  many  other  cities  are  interested  in  this  method  of  obtaining 
an  accurate  record  at  a  reasonable  cost  of  the  amount  of  sew- 
age handled.  See  Fig.  69. 

Weirs  have  been  installed  at  appropriate  places  in  some 
systems,  with  an  automatic  water  stage  register  to  keep  a  record 
of  the  depth  of  sewage  on  the  crest  of  the  weir.  The  ob- 

*By  Mr.  Warren  E.  Hall,  M.  Am.  Soc.  C.  E.,  District  Engineer,  U.  S. 
Geological  Survey. 


WATER    STAGE    REGISTERS  131 

jection  is  sometimes  raised  that  the  introduction  of  a  weir  in 
the  line  of  flow  may  cause  an  accumulation  of  sludge  deposits 
back  of  the  weir.  This  may  be  provided  for  by  making  an 
ample  outlet  to  the  weir  cnamber  through  a  quick  opening 
valve  by  which  the  contents  of  that  chamber  may  be  rapidly 
and  easily  discharged. 

In  the  design  of  sewage  disposal  plants  the  quantity  of 
sewage  to  be  handled  by  the  plant  is  one  of  the  controlling  fac- 
tors. This  factor  may  be  determined  by  the  methods  indicated, 
but  it  should  be  noted  that  the  information  required  is  not  such 
as  may  be  obtained  overnight,  but  that  its  collection  will  likely 
extend  over  a  considerable  time.  Therefore,  cities  contemplat- 
ing installations  of  this  kind  should  be  forehanded  in  the 
matter  of  obtaining  data. 

SOUNDINGS  AND  TIDE  GAGES 

When  conducting  soundings  for  hydrographic  surveys 
from  which  to  make  charts  of  tidal  waters,  it  is  necessary  to 
keep  a  record  of  the  stage  of  the  tide  so  that  the  soundings, 
which  are  taken  to  the  surface  of  the  water,  may  be  referred  to 
a  permanent  datum.  Recording  water  stage  registers  have 
been  used  successfully  on  such  work.  They  also  find  a  similar 
use  in  keeping  a  record  of  stage  on  tidal  rivers. 

NAVIGATION  CANALS 

It  is  frequently  desirable  to  keep  a  record  of  the  flow  of 
navigation  canals.  Because  of  the  quantity  of  water  used  at 
the  locks,  the  slope  of  the  water  surface  varies  from  time  to 
time,  so  that  a  record  from  a  single  recording  register  is  not 
successful.  In  such  cases  the  method  that  should  be  used  is 
that  explained  in  detail  by  Messrs.  Hall,  Pierce,  and  Hall,  in 
Water  Supply  Paper  345  E,  U.  S.  Geological  Survey.  In  this 
method  the  estimates  of  daily  discharge  are  based  on  both  the 
gage  height  and  the  surface  slope  between  two  stations  a  suffi- 
cient distance  apart,  the  hydraulic  radius  at  sections  between 
them  being  constant.  The  registers  should  be  located  far 
enough  apart  to  show  any  appreciable  change  in  slope,  and  it  is 
absolutely  necessary  that  they  be  set  to  the  same  datum.  Auto- 
matic recording  water  stage  registers  should  be  used.  See  Figs. 
70,  71  and  72,  page  132. 


WATER    STAGE    REGISTERS  133 

IRRIGATION  CANALS 

In  all  open  channels  in  which  a  control  section  may  be 
established  at  which  the  relation  of  gage  height  and  discharge 
is  constant,  the  current  meter  may  be  used  with  success,  the 
gage  heights  bein'g  recorofed  by  automatic  registers.  Such 
methods  are  applicable  to  main  irrigation  canals  and  main 
laterals  of  irrigation  systems.  The  introduction  of  checks 
into  the  subsidiary  distributing  channels  in  the  course 
of  their  ordinary  operation  causes  backwater  along  their  en- 
tire length,  the  slope  being  very  small,  and  this  makes  it  im- 
possible to  use  current  meter  stations  which  depend  on  continu- 
ous control  for  their  successful  operation. 

HYDRAULIC  POWER  STATIONS 

The  problem  of  making  efficient  use  of  the  water  available 
for  use  in  water  wheels  is  constantly  before  operators  of  hy- 
draulic power  stations.  The  results  of  many  tests  show  that 
operators  heretofore  have  often  failed  to  check  up  with  suffi- 
cient care  the  hydraulic  efficiency  of  their  wheels  to  be  sure 
that  they  are  getting  all  of  the  energy  possible  out  of  their 
installation.  Frequently,  obstructions  of  various  kinds  have 
reduced  the  flow  into  the  water  wheels  to  such  an  extent  that 
they  are  operating  at  an  efficiency  far  below  the  manufacturers 
rating. 

It  is  now  customary  at  well  operated  power  stations  to 
keep  careful  records  by  means  of  which  a  loss  of  efficiency  in 
the  operation  of  the  plant  is  quickly  detected  and  localized. 
Operating  efficiency  requires  that  records  be  kept  of  the  height 
of  water  in  the  forebay,  the  height  in  the  tailrace,  and  the 
height  of  water  flowing  over  the  spillway  of  the  dam.  It  is 
possible  to  keep  such  records  continuously  by  means  of  Gurley 
automatic  water  stage  registers. 

FLUMES 

Automatic  water  stage  registers  may  be  used  to  advantage 
on  flumes  that  have  been  rated  in  a  proper  manner.  In  such- 
cases  the  record  of  stage  is  made  by  the  water  stage  register, 
and  this  record  is  applied  to  a  table  of  discharge. 

WEIRS 

A  similar  application  of  automatic  registers  is  desirable 
at  weirs  for  measuring  flow  in  cases  where  the  head  on  the 
weir  varies. 


FIG.  73. — Typical  Installations  of  Gurley  Printing  and  Graphic  Water  Stage 
Registers  by  the  Stone  &  Webster  Engineering  Corporation,  for  the  Missis- 
sippi River  Power  Company,  which  used  seventeen  Gurley  Registers  to 
obtain  accurate  records  for  the  efficient  operation  of  its  power  plant  at 
the  Keokuk  Dam.  Views  A  and  B  show  two  of  the  four  Printing  Registers 
used  to  obtain  elevations  in  the  forebay  and  tailrace  of  the  power  house. 
Views  C,  D  and  K  show  installations  along  the  Mississippi  River  at  con- 
siderable distances  above  and  below  the  dam  at  Keokuk. 


WATER     STAGE    REGISTERS 


135 


FIG.  74. —  Installation  of  a  Gurley  Printing  Register  by  the  U.  S.  Geological 

Survey  on  Alplaus  Creek  near  Charlton,  N.  Y.,   to  record 

the  flow  over  a  V-notch  weir. 

If  refined  measurements  are  required  the  coefficients  used 
in  the  weir  formula  by  which  the  discharge  is  computed  should 
be  obtained  from  an  actual  rating  of  the  weir  used.  Weir 
coefficients  that  are  obtained  in  the  laboratory  do  not  apply 
accurately  to  weirs  used  in  the  field,  unless  they  are  of  the 
same  design  and  are  set  up  in  the  field  and  used  under  the 
same  conditions  that  existed  when  they  were  rated. 

The  following  precautions  should  be  observed  when  using 
weirs  in  the  field: 

No  water  should  be  allowed  to  leak  past  the  ends  of  the 
weir  nor  under  it.  In  the  case  of  permanent  weirs  special  pre- 
cautions are  taken  during  construction  to  guard  against  such 
defects.  In  the  case  of  temporary  weirs  particular  attention 


136         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

must  be  paid  to  this  detail.  Gunny  sacks  are  frequently  used 
with  temporary  weirs  to  prevent  leaks.  Sand  bags  and  puddles 
have  also  been  used. 

The  water  should  fall  freely  over  the  crest  of  the  weir  and 
the  distance  from  the  crest  to  the  bottom  of  the  channel  in 
which  it  is  inserted  should  be  greater  than  three  times  the  head 
of  water  on  the  crest  in  order  not  to  suppress  the  contraction. 
For  the  same  reason,  on  a  weir  with  end  contractions  the  dis- 
tance between  the  edges  of  the  weir  and  the  sides  of  the  chan- 
nel should  be  three  times  the  depth  of  the  crest.  The  depth 
of  water  on  the  crest  of  a  weir  is  usually  much  less  than  the 
breadth  of  the  crest.  The  depth  should  be  not  less  than  0.1 
foot  nor  more  than  4.5  feet,  in  order  to  keep  within  the  range  of 
tests  on  the  standard  weir.  The  breadth  of  the  crest  ordinarily 
ranges  between  0.5  foot  and  20  feet.  The  maximum  discharge 
that  can  be  gaged  conveniently  on  a  weir  20  feet  long  is  about 
200  second  feet. 

If  the  water  approaches  the  crest  of  the  weir  with  a  velocity 
exceeding  0.5  foot  per  second,  a  discharge  formula  involving 
velocity  of  approach  should  be  used. 

The  automatic  water  stage  register  should  be  placed  far 
enough  upstream  from  the  crest  of  the  weir  to  be  beyond  the 
curve  taken  by  the  water  as  it  approaches  the  weir. 

A  full  discussion  of  the  theory  of  weir  measurements  will 
be  found  in  text  books  on  Hydraulics,  many  of  which  include 
tables  that  facilitate  computations  of  discharge.  In  Water 
Supply  Paper  No.  200,  U.  S.  Geological  Survey,  will  be  found 
a  valuable  discussion  by  Mr.  R.  E.  Horton,  M.  Am.  Soc.  C.  E.,  of 
many  weir  experiments. 


SUGGESTIONS  FOR  THE  SELECTION   OF  AUTOMATIC 
WATER  STAGE  REGISTERS 

There  are  two  classes  of  automatic  water  stage  registers. 
One  class  makes  a  continuous  printed  record  of  stage  and  time; 
the  other  class  makes  a  graphic  record  of  stage  and  time. 

In  selecting  an  automatic  water  stage  register  careful 
attention  should  be  given  to  the  conditions  under  which  it  is 
required  to  work,  and  to  the  type  of  record  required. 


WATER    STAGE    REGISTERS  137 

PRINTING   REGISTERS 

The  printing  register  is  especially  well  adapted 

(1)  To  situations  that  require  a  record  in  type. 

(2)  To  inaccessible  locations. 

(3)  As  a  convenience  in  operation  at  other  stations. 

(4)  Where  only  non-technical  assistance  is  available 

to  compute  the  records. 

Printed  records  of  stage  and  time  have  a  single  definite 
meaning  and  hence  are  not  affected  by  personal  equation  when 
used  by  different  individuals.  For  this  reason  printed  records 
are  particularly  well  adapted  to  those  situations  in  which  a 
legal  interpretation  of  the  record  is  to  be  made.  They  are 
also  well  adapted  to  the  use  of  water  commissioners,  operators, 
and  owners  without  technical  training  in  the  use  of  graphic 
records. 

When  the  record  is  to  be  made  at  a  location  which  is  not 
easily  accessible  and  hence  at  which  it  is  necessary  to  have  a 
reliable  and  readily  interpreted  long  time  record,  unaffected 
by  weather  conditions,  the  printing  register  meets  fully  all  of 
the  requirements.  Gurley  Printing  Registers  have  operated 
continuously  in  many  situations  of  this  kind  for  six  months 
without  attention. 

At  many  locations  the  record  sheets  must  be  changed  by 
assistants  who  are  not  able  to  follow  a  regular  schedule.  At 
such  places  continuity  of  the  record  of  the  printing  register  is 
unaffected  by  such  irregularity. 

Printing  records  are  easily  compiled.  It  is  often  con- 
venient to  have  such  work  done  by  power  house  operators  or 
others  not  familiar  with  graphic  processes.  Printed  records 
lend  themselves  readily  to  such  uses. 

Printing  registers  record  the  stage  to  single  hundredths  of 
a  foot.  The  frequency  of  the  record  may  be  varied  within 
certain  limits  to  suit  the  requirements  of  particular  cases.  As 
ordinarily  constructed,  Gurley  Printing  Registers  print  the  record 
at  intervals  of  fifteen  minutes,  but  it  is  possible  to  arrange 
registers  to  print  every  half  hour,  or  every  hour. 

GRAPHIC  REGISTERS 

Gurley  Graphic  Registers  give  an  accurate  hydrograph, 
or  curve,  showing  the  relations  between  stage  and  time. 


138         W.  &  L.  E.  GURLEY,  TROY,  N.  Y. 

One  type  (No.  633  —  see  Fig.  50,  page  103)  makes  a 
reduced  size  record  of  stage,  while  the  other  (No.  634  —  see 
Fig.  54,  page  111)  makes  a  full  size  natural  scale  record. 
The  scale  of  stage  should  be  selected  so  as  to  allow  the  gage 
height  to  be  read  to  the  required  degree  of  fineness.  This  is 
decided  in  accordance  with  the  precision  required  in  each  par- 
ticular case  after  considering  the  percentage  effect  on  discharge 
of  different  variations  of  gage  height.  The  range  of  stage  is 
usually  selected  so  that  ordinary  fluctuations  of  stage  are 
recorded  entirely  within  the  range  of  a  single  turn  of  the 
cylinder.  This,  however,  is  merely  a  matter  of  convenience, 
because  the  cylinder  will  continue  to  revolve  and  extraordinary 
fluctuations  of  stage  will  be  properly  recorded,  the  range  of 
stage  being  unlimited. 
The  Graphic  Register  is  especially  adapted 

(1)  To  general  stream  gaging  work. 

(2)  To  permanent  intallation  at  power  plants. 

(3)  To  use  in  sewage  disposal  plants. 

(4)  To  use  in  sanitary  sewers. 

(5)  To  use  in  reservoirs. 

(6)  As  a  portable  gage  in  making  special  studies. 
The  utility  of  all    stream   flow   records    is   based    on    an 

accurate,  dependable  record  of  gage  heights  or  water  stage. 
Such  records  are  clearly  made  on  properly  ruled  coordinate 
paper  by  Gurley  Graphic  Water  Stage  Registers.  They  are 
easily  installed  and  are  exact  and  constant  in  their  opera- 
tion, having  been  developed  to  meet  actual  field  conditions, 
and  require  a  minimum  amount  of  attention.  The  record  is  a 
continuous  curve  covering  seven  days  time.  The  record  sheet 
must  be  changed  at  least  every  seven  days,  but  is  of  sufficient 
length  to  allow  some  variation  in  the  exact  time  of  making 
the  change. 

The  graphic  record  shows  at  a  glance  the  stage  and  time 
relations,  and  is  easily  interpreted.  It  is  adapted  to  any 
graphic  method  of  calculation.  The  range  of  stage,  which  is 
unlimited,  is  adjusted  to  particular  needs  by  the  use  of  proper 
gear  combinations  to  give  an  appropriate  scale  ratio  for  stage. 
The  time  scale  is  ordinarily  one  inch  per  hour,  but  time 
screws  can  be  furnished  to  give  a  one  day,  or  four  day,  time 
scale. 


WATER    STAGE    REGISTERS  139 

Accurate  information  in  regard  to  the  water  stage  in  both 
forebay  and  tailrace  at  all  water  power  stations  is  necessary. 
At  such  stations  Gurley  Graphic  Registers  afford  a  method  of 
obtaining  and  recording  the  required  information  in  convenient 
form.  Provision  should  4)e  made  in  designing  the  power  plant 
and  its  accessories  for  the  proper  installation  (See  page  134) 
of  water  stage  registers. 

Such  records  frequently  prevent  disputes  and  often 
assume  great  importance  in  legal  actions  concerning  the  use 
of  the  water. 

The  successful  operation  of  sewage  disposal  works  re- 
quires an  accurate  knowledge  of  the  quantity  of  sewage  to  be 
treated.  Such  knowledge  may  readily  be  obtained  by  the  use 
of  Gurley  Graphic  Registers  properly  installed.  The  quantity 
of  effluent  discharged  and  its  degree  of  dilution  may  also  be 
determined  by  such  use.  See  page  130. 

The  quantity  of  sewage  flowing  in  trunk  sewers  or  in 
intercepting  sewers  may  be  readily  determined  by  the  use  of 
Gurley  Water  Stage  Registers.  This  information  is  essential 
to  and  should  preceed  the  design  of  sewage  disposal  works. 

A  record  of  the  height  of  water  in  reservoirs,  and  its  fluc- 
tuation, is  easily  obtainable  by  the  use  of  such  registers.  This 
is  desirable  in  all  reservoirs  of  any  domestic  water  supply 
system.  Such  records  aid  in  the  successful  operation  of  the 
systems.  The  head  and  its  fluctuations  are  very  important 
elements  of  efficient  operation  where  water  is  pumped  into  dis- 
tributing reservoirs.  In  such  situations  records  are  essential. 

Many  industrial  operations  require  the  storage  in  tanks 
or  reservoirs  of  liquid  materials,  the  quantity  of  which  it  is 
desirable  to  record.  Gurley  Graphic  Registers  are  well  adapted 
to  such  requirements.  They  present  in  compact  form  a  con- 
venient record  of  such  manufacturing  processes. 

The  accurate  determination  of  gage  heights  is  an  impor- 
tant part  of  many  special  hydraulic  investigations.  The 
graphic  type  of  record  is  especially  valuable  in  such  work, 
because  of  the  form  in  which  the  record  is  presented.  The 
possibility  of  varying  the  scale  of  the  record,  which  may  be 
accomplished  by  an  alteration  of  the  gear  relations  on  Register 
No.  633  (See  page  101),  makes  it  the  most  flexible  register 
on  the  market  for  such  studies. 


INDEX 


Page 

Accuracy  of  current  meter  62 

Acoustic  current  meter  21,  22 

Advantages  of  Gurley  current  meters  28 
American  Society  of  Civil  Engineers, 

Transactions  of,  reference  to  ....  62 

Applications  of  current  meters  and 

water  stage  registers 128-136 

Artificial  channels,  current  meters 

measurements  in  62 

Automatic  Water  Stage  Registers. 

See  Registers. 

Batteries,  dry,  for  current  meters  ...  18,  33 

Bench  marks,  establishment  and  use  of  75,  76 
Boats,  current  meter  measurements 

from  39,  40 

Bridges,  current  meter  measurements 

from  47 

Bridges,  installation  of  registers  at.  122,  126 

Bureau  of  Standards  rating  station..  33,  35 

Cables,     current    meter    measurements 

from     44-46 

Cables   for  suspending   current  meters 

19,  20,   27,  44 
Canals,   irrigation,   use  of  water  stage 

registers   on    133 

Canals,  navigation,  use  of  water  stage 

registers    on    131,  132 

Care    of   the   current    meter    30-33 

Catamaran,   use  of,   in  making  current 

meter   measurements    39,  40 

Chain   gages    74 

Channels,      artificial,      current      meter 

measurements    in    62 

Computation  and  care  of  water  stage 

register    records    122,    127,    128 

Conduits,   use  of  current  meter  in   ...  62 

Construction   of    current    meters    14-20 

Construction    of    graphic    water    stage 

registers     104-106,  112-115 

Construction    of   hook    gage    73 

Construction    of   printing    water    stage 

registers     90-96 

Control   of   a   stream    40,  41 

Corps     of     Engineers,     TT.     S.     Army, 

reference  to    13 

Covert,   C.    C.,    references    to    25,   65 

Current  meter  field  outfit,  complete.  .  29,  30 
Current  meter  measurements  in  low 

water     57,  59 

Current  meter  measurements,  types  of  39-47 
Current  metef1  measurements  under  ice  58-61 
Current  meter  rating  stations  33-35 


Page 

Current    meters,     accuracy    and    relia- 
bility   of 62 

Current  meters,    advantages  of    28 

Current  meters   and   water   stage   reg- 
isters,   applications    of    129-136 

Current    meters,    care    of    30-33 

Current    meter    circuits,      methods     of 

testing     32 

Current  meters,    construction   of    14-20 

Current    meters,    essentials    of    14 

Current   meters,    rating   of    33-38 

Current    meters,    selection    of    21-28 

Current   meters,    use   of    48-62 

Dam    at    Keokuk,    reference   to 134 

Dams,   installation  of  registers  at    ...         122 
Data,    recording    of   current    meter  .  .  .     52-57 
Data,    recording    of   water   stage   reg- 
ister      122,   127,   128 

Electric    current    meters    16,    22-26 

Electric  register  for  use  with  current 

meters     26 

"Engineering  News,"  references  to*  51,  56,  128 
Essential    features    of    current    meter          14 
Essential  parts   of  current  meter    ....  13 
Establishment    of    current   meter   gag- 
ing  stations    70,  71 

Float    gages    74 

Flumes,   use  of  hook  gage   on 73 

Flumes,    use   of   water  stage   registers 

on      133 

Gage,   hook    73,  74 

Gages,    chain    74 

Gages,    float    74 

Gages,    non-recording     71-75 

Gages,      recording;      or     water      stage 

registers     75,     77-117 

Gages,    staff    71,  72 

Gaging  stations.    See   Stations. 
Geological    Survey,    TJ.    S.,    references 

to 13,    24,    25,    37,    44,    49,    70, 

71,    76,    77,    96,    118,    123,    125,    126,    127, 

132,    135,    136. 
Graphic  water  stage  registers,    1   foot 

range,    advantages    of    110,112 

Graphic  water  stage   registers,    1   foot 

range,    construction    of    112,113 

Graphic  water  stage  registers,    1   foot 

range,    installation    and    operation 

of    .  113,  115 


INDEX 


Page 
Graphic  water  stage  registers,  record 

sheets  for  1,16,  117 

Graphic  water  stage  registers,  10  foot 

range,  advantages  of  101-104 

Graphic  water  stage  registers,  10  foot" 

range,  construction  of  104-106 

Graphic  water  stage  registers,  10  foot 

range,    installation    and    operation 

of  107-109 

Gray,  G.  A.,  reference  to  77 

Grover,  N.  C.,  and  Hoyt,  J.  C.  See 

"River  Discharge." 

Hall,    Pierce    and    Hall,    reference    to        131 

Hall,   W.    E.,   reference   to    130 

Hancock's         "Applied        Mechanics," 

reference  to    50 

Hanna,    F.    W.,    reference    to    51 

Head   line   for  holding   current   meters 

vertical     4* 

Hook    gages,    description    and    use    of     71-74 

Horton,    R.    E.,    reference   to    136 

Hoyt,    J.    C.    and    Grover,    N.    C.      See 

"River    Discharge." 

Hoyt,    J.    C. ,    reference   to    13 

Hydraulic     power     stations,      use     of 

water   stage   registers   at    133,  134 

Ice,  measurements  under  58-61 

Indicating  or  recording  devices  for 

current  meters  18,  19 

Installation  and  operation  of  graphic 

water  stage  registers...  107-109,  113-117 
Installation  and  operation  of  printing 

water  stage  registers 96-100 

Installation  and  shelter  of  water  stage 

registers  118-122 

Instructions  for  care  of  current  meter  30-33 
Irrigation  canals,  use  of  water  stage 

registers    on    133 

Keokuk     Dam     of     Mississippi     River 

Power    Company,    reference    to ...        134 

Location     of     current     meter     gaging 

stations     63-71 

Lyon,    George    J.,    reference   to 70 

Measurements,  current  meter,  types  of    39-47 

Measurements    from    bridges     47 

Measurements    from    cables    44-46 

Measurements     in     artificial     channels          62 

Measurements,    low    water    57,  59 

Measurements   of    sewage    129-131 

Measurements    under    ice     58-61 

Measurements,   wading    42,  43 

Meters,   current.      See  Current  meters. 


Page 
Mississippi     River     Power      Company, 

reference   to    134 

Navigation  canals,  use  cf  water  stage 

registers  on  131,  133 

New  York  State  Barge  Canal,  refer- 
ence to  132 

Notes,    form    for    recording    register.  .         127 

Notes,  forms  for  current  meter.  .  29,  54,  55,  60 

Observations,  velocity,  with  the  cur- 
rent meter  49-52 

Observers      70 

Oil    device    for    use    in    water    stage 

register  wells    120,  121 

Oiling  of  water  stage  registers    100,  109,  115 
Operation    of    water    stage    registers. 

See  Installation. 
Outfit,     complete    current    meter    field  29,  30 


Panama-Pacific  International  Exposi- 
tion, reference  to  4,  8 

Pierce,    C.    H.,    reference   to    77 

Portable  shelters  for  water  stage 

registers  118,  122 

Power  stations,  hydraulic,  use  of  water 

stage  registers  at  133,  134 

Price,    W.  G.,    reference    to     13 

Printing  water  stage  register,  advan- 
tages of  86,  88 

Printing  water  stage  register,  con- 
struction of  90-96 

Printing  water  stage  register,  instal- 
lation and  operation  of  96-100 

Rating    stations    for    current    meters          35 

Rating   the    current  meter    33-38 

Reconnoissance       to       locate       gaging 

stations 63-70 

Recording  gages.      See  Registers. 

Recording  of  current  meter  data 52-57 

Recording    or    indicating    devices    for 

current    meters    18,  19 

Record  sheets  for  graphic  water  stage 

registers    116,  117 

Records,    water    stage    register,    care 

and    computation    of    122,  127,  128 

Reduction    tables    for    current    meters     36-38 

Reel   for  use  with   current   meter 20 

Reel,    tape,    for     use     with     printing 

registers     90 

Registers,      water     stage,      conditions 

requiring    use    of    77-81 

Registers,       water      stage,       essential 

features  of    81-85 

Registers,    water    stage,     graphic;      1 

foot  range;  advantages  of   110,  112 


INDEX 


Page 

Registers,  water  stage,  graphic;  1 

foot  range;  construction  of 112,113 

Registers,  water  stage,  graphic;  1 
foot  range;  installation  and  oper- 
ation of  113-115 

Registers,  water  stage,  graphic,  10 

foot  range;  advantages  of  101-104 

Registers,  water  stage,  graphic,  10 

foot  range;  construction  of  104-106 

Registers,  water  stage,  graphic,  10 
foot  range;  installation  and  oper- 
ation of  107-109 

Register,  water  stage,  printing;  ad- 
vantages of  86,  88 

Register,  water  stage,  printing;  con- 
struction of  90-96 

Register,  water  stage,  printing;  in- 
stallation and  operation  of  96-100 

Registers,  water  stage,  suggestions 

for  selection  of  136-139 

Reliability   of   current   meters    62 

"River  Discharge,"  references  to 

13,  35,  51,  70 

Rods,    wading,    for   current    meters...          25 

Russian  Government  Engineers,  refer- 
ence to  46 

Selecting  proper  type  of  current  meter  21-28 
Selection  of  water  stage  registers, 

suggestions   for    136-139 

Sewage  disposal  plants,  use  of  regis- 
ters at  131,  139 

Sewage,    measurement    of    129-131 

Sewers,  installation  of  registers  in.  .129,  130 
Sewers,  use  of  current  meter  in  ....129-131 
Shelters  for  water  stage  registers  118-126,  132 
Soundings  and  tide  gaging,  use  of 

water   stage  registers   for    131 

Soundings    by    use    of    current    meter  48,  49 

Staif  gages    71,  72 

Stations,  current  meter  gaging,  selec- 
tion and  location  of  63-71 


Page 

Stations     for     rating     current     meters          35 
Stations,  hydraulic  power,  use  of  water 

stage    registers    at     133,134 

Stevens,   J.   C.,   reference  to   56 

Stone  and  Webster  Engineering  Cor- 
poration, reference  to  134 

Stream  control   40,  41 

Tables,   reduction,    for   current   meters     36-38 
Tide  gaging,  use  of  water  stage  regis- 
ters for 131 

Type      of      current      meter,      selecting 

proper    21-28 

United  States  Bureau  of  Standards, 

references  to 33,  35 

United  States  Engineer  Department, 

reference  to  124 

United  States  Geological  Survey. 
See  Geological  Survey. 

Use   of   current    meter    48-62 

Velocity  observations  with  the  cur- 
rent meter 49-52 

V-notch  weir,  use  of  water  stage  reg- 
isters at 135 

Wading  measurements  with  the  cur- 
rent meter  42,  43 

Wading    rods    for    use     with     current 

meters     25 

Water    stage    registers      and      current 

meters,    applications    of    128-136 

Water  stage  registers.      See  Registers. 
Weighted  mean  gage  height,  to  obtain          57 

Weirs,   use   of   hook   gage   at    73,  74 

Weirs,    use    of    water    stage    registers 

at   133,   135,    136 

Wells  for  water  stage  registers 119,  120 

Winter  measurements  with  the  cur- 
rent meter  58-61 


W.  &  L.  E.  GURLEY 

Established  1845 
Manufacturers  of 

ENGINEERING  AND  SURVEYING  INSTRUMENTS 

Transits  Compasses  Hand  Levels 

Levels  Leveling  Rods  Plummets 

Alidades  Stadia  Rods  Tripods 

Plane  Tables  Leather  Cases  Chains 

Sketching  Cases  Leather  Pouches 

Dealers  in 
Small  Field  Instruments  and  Accessories. 

Drawing  Instruments  and  Office  Supplies. 
Illustrated  Catalogue  sent  free  to  any  interested  engineer,  on  request. 


YC  33139 


945358 


cm 

G-3 


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